Net Loss per Share - Schedule of Potentially Dilutive Securities Excluded from Computation of Net Loss per Share (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2023	Jul. 31, 2022	Jul. 31, 2023	Jul. 31, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted net loss per share (in shares)	51,857	53,241	51,857	53,241
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted net loss per share (in shares)	30,893	38,163	30,893	38,163
RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted net loss per share (in shares)	20,497	14,337	20,497	14,337
Unvested restricted common stock and early exercised stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted net loss per share (in shares)	291	641	291	641
Employee stock purchase rights under the 2020 ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted net loss per share (in shares)	176	100	176	100