CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ EQUITY - Capital Stock (Details) - shares	Sep. 30, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Convertible preferred stock, authorized (in shares)	50,000,000	50,000,000
Convertible preferred stock, outstanding (in shares)	0	0
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, shares outstanding (in shares)	44,099,239	33,499,953
2020 Employee, Director, and Consultant Equity Incentive Plan
Class of Stock [Line Items]
Capital shares reserved for future issuance (in shares)	2,119,223
Warrant
Class of Stock [Line Items]
Capital shares reserved for future issuance (in shares)	18,236
Restricted stock units
Class of Stock [Line Items]
Capital shares reserved for future issuance (in shares)	1,276,188
Stock options
Class of Stock [Line Items]
Capital shares reserved for future issuance (in shares)	799,044