Quarterly Results of Operations (Unaudited) - Schedule of Consolidated Statements of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Revenue
Total revenue	$ 42,110	$ 41,230	$ 39,080	$ 35,180	$ 31,684	$ 28,244	$ 25,999	$ 22,424	$ 157,600	$ 108,351	$ 64,865
Cost of revenue	10,100	10,110	9,787	9,147	8,488	7,914	7,175	6,341	39,144	29,918	19,372
Gross profit	32,010	31,120	29,293	26,033	23,196	20,330	18,824	16,083	118,456	78,433	45,493
Operating expenses
Research and development	14,929	13,969	12,992	11,515	9,447	7,899	6,154	5,424	53,405	28,924	17,986
Sales and marketing	11,796	11,802	11,491	10,267	9,949	7,365	6,856	5,944	45,356	30,114	19,290
General and administrative	15,546	15,064	12,748	10,535	8,953	7,904	6,404	5,937	53,893	29,198	16,034
Total operating expenses	42,271	40,835	37,231	32,317	28,349	23,168	19,414	17,305	152,654	88,236	53,310
Loss from operations	(10,261)	(9,715)	(7,938)	(6,284)	(5,153)	(2,838)	(590)	(1,222)	(34,198)	(9,803)	(7,817)
Other income, net	764	1,397	360	639	596	734	686	317	3,160	2,333	632
Loss before provision for (benefit from) income taxes	(9,497)	(8,318)	(7,578)	(5,645)	(4,557)	(2,104)	96	(905)	(31,038)	(7,470)	(7,185)
Provision for (benefit from) income taxes	1	1	0	51	(59)	(70)	(6)	(21)	53	(156)	10
Net loss	$ (9,498)	$ (8,319)	$ (7,578)	$ (5,696)	$ (4,498)	$ (2,034)	$ 102	$ (884)	$ (31,091)	$ (7,314)	$ (7,195)
Net (loss) income per share attributable to common stockholders, basic and diluted	$ (0.13)	$ (0.11)	$ (0.34)	$ (0.69)	$ (0.56)	$ (0.26)	$ 0	$ (0.12)	$ (0.70)	$ (0.94)	$ (1.01)
Subscription and Transaction Fees
Revenue
Total revenue	$ 38,801	$ 36,092	$ 32,964	$ 28,548	$ 25,225	$ 22,112	$ 20,444	$ 18,170	$ 136,405	$ 85,951	$ 56,992
Interest on Funds Held for Customers
Revenue
Total revenue	$ 3,309	$ 5,138	$ 6,116	$ 6,632	$ 6,459	$ 6,132	$ 5,555	$ 4,254	$ 21,195	$ 22,400	$ 7,873