Stockholders' Equity - Schedule of Common Stock Reserved for Issuance (Detail) - shares	6 Months Ended	12 Months Ended
	Sep. 30, 2022	Mar. 31, 2022
Class Of Stock [Line Items]
Outstanding stock options	69,845,695	73,609,565
Total shares of common stock reserved	151,345,269	144,601,515
2021 Equity Incentive Plan
Class Of Stock [Line Items]
Remaining shares available for future issuance under 2021 Equity Incentive Plan	46,248,242	48,895,572
Employee Stock Purchase Plan
Class Of Stock [Line Items]
Remaining shares available for future issuance under Employee Stock Purchase Plan	10,289,663	11,420,000
Restricted Stock Units [Member]
Class Of Stock [Line Items]
Outstanding restricted stock units	24,961,669	10,676,378