The Company and Its Significant Accounting Policies - Additional Information (Details)			12 Months Ended
	Jun. 15, 2020 USD ($) $ / shares shares	Dec. 16, 2019 USD ($) $ / shares shares	Jun. 30, 2021 USD ($) Segment Customer	Jun. 30, 2020 USD ($) Customer shares	Jun. 30, 2019 USD ($) Customer	Jul. 01, 2020 USD ($)
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Proceeds from issuance of common stock upon initial public offering, net of underwriting discounts and commissions and other offering costs		$ 225,500,000		$ 225,481,000
Reclassification of redeemable convertible preferred stock warrant liabilities to additional paid-in capital upon initial public offering		$ 1,400,000		1,405,000
Net proceeds from follow-on public offering	$ 307,500,000
Number of operating segments | Segment			1
Other-than-temporary impairment on short-term investments			$ 0	$ 0	$ 0
Allowance for potential credit losses related to accounts receivable and acquired card receivables			1,900,000
Allowance for potential credit losses for acquired card receivables			$ 1,700,000
Number of reporting unit | Segment			1
Offering period of purchase rights under ESPP			1 year
Risk-free interest rate			0.00%
Expected dividend yield			0.00%	0.00%	0.00%
Advertising expenses			$ 8,500,000	$ 5,800,000	$ 3,700,000
Operating lease right-of-use assets, net			71,925,000
Operating lease, liabilities			$ 97,403,000
ASU 2016-02
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]			true
Change in Accounting Principle, Accounting Standards Update, Adoption Date			Jul. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]			true
Operating lease right-of-use assets, net						$ 44,200,000
Operating lease, liabilities						49,700,000
Deferred rent liabilities						13,700,000
ASU 2019-08
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]			true
Change in Accounting Principle, Accounting Standards Update, Adoption Date			Jul. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]			true
ASU 2018-15
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]			true
Change in Accounting Principle, Accounting Standards Update, Adoption Date			Jul. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]			true
ASU 2018-13
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]			true
Change in Accounting Principle, Accounting Standards Update, Adoption Date			Jul. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]			true
ASU No. 2018-07
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]			true
Change in Accounting Principle, Accounting Standards Update, Adoption Date			Jul. 01, 2020
Expected to recognize stock based compensation expense						$ 1,800,000
ASU 2016-13
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]			true
Change in Accounting Principle, Accounting Standards Update, Adoption Date			Jul. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]			true
Stock Options and RSUs
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Vesting term			4 years
Sales and Marketing Expenses
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Rewards and promotions expense			$ 4,500,000
Other Accruals and Current Liabilities
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Accrued rewards and promotions liability			$ 19,200,000
Minimum
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Estimated useful lives			1 year
Estimated useful lives			3 years
Lease arrangements term			12 months
Deferred sales commissions are amortized			4 years
Maximum
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Estimated useful lives			3 years
Estimated useful lives			8 years
Deferred sales commissions are amortized			10 years
Revenue Benchmark | Customer Concentration Risk
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Number of customers exceed 10% of revenue | Customer			0	0	0
Revenue Benchmark | Customer Concentration Risk | No Customer
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Concentration percentage			10.00%	10.00%	10.00%
Common Stock
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Shares issued | shares				11,297,000
Redeemable convertible preferred stock converted | shares		52,434,505
IPO
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Shares issued | shares	4,330,000	11,297,058
Shares issued price to public per share | $ / shares	$ 74.25	$ 22.00
Underwriting discounts and commissions		$ 17,400,000
Other offering costs		$ 5,600,000
Over-Allotment Option
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Shares issued | shares	1,080,000	1,473,529
Follow-On Public Offering
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Underwriting discounts and commissions	$ 12,900,000
Other offering costs	$ 1,100,000
Follow-On Public Offering | Common Stock
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Shares issued | shares				4,330,000