Condensed Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholder's Equity (Deficit) - USD ($) $ in Thousands	Total	Preferred Stock Series A [Member]	Preferred Stock Series A-1 [Member]	Preferred Stock Series B [Member]	Preferred Stock Series B-1 [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2019	$ (58,902)	$ 9,569	$ 14,083	$ 18,854	$ 4,682	$ 2	$ 2,293	$ (61,197)
Beginning balance (in shares) at Dec. 31, 2019		26,157,622	20,238,201	12,366,306	3,047,183	21,700,713
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options	50						50
Issuance of common stock upon exercise of stock options (in Shares)						241,444
Stock-based compensation	181						181
Net loss	(2,128)							(2,128)
Ending balance at Mar. 31, 2020	(60,799)	$ 9,569	$ 14,083	$ 18,854	$ 4,682	$ 2	2,524	(63,325)
Ending balance (in shares) at Mar. 31, 2020		26,157,622	20,238,201	12,366,306	3,047,183	21,942,157
Beginning balance at Dec. 31, 2019	(58,902)	$ 9,569	$ 14,083	$ 18,854	$ 4,682	$ 2	2,293	(61,197)
Beginning balance (in shares) at Dec. 31, 2019		26,157,622	20,238,201	12,366,306	3,047,183	21,700,713
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(4,723)
Ending balance at Sep. 30, 2020	(62,610)	$ 9,569	$ 14,083	$ 18,854	$ 4,682	$ 2	3,308	(65,920)
Ending balance (in shares) at Sep. 30, 2020		26,157,622	20,238,201	12,366,306	3,047,183	22,033,268
Beginning balance at Mar. 31, 2020	(60,799)	$ 9,569	$ 14,083	$ 18,854	$ 4,682	$ 2	2,524	(63,325)
Beginning balance (in shares) at Mar. 31, 2020		26,157,622	20,238,201	12,366,306	3,047,183	21,942,157
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock warrants in connection with debt amendment and new debt issuance	226						226
Issuance of common stock upon exercise of stock options	19						19
Issuance of common stock upon exercise of stock options (in Shares)						30,669
Stock-based compensation	273						273
Net loss	(1,094)							(1,094)
Ending balance at Jun. 30, 2020	(61,375)	$ 9,569	$ 14,083	$ 18,854	$ 4,682	$ 2	3,042	(64,419)
Ending balance (in shares) at Jun. 30, 2020		26,157,622	20,238,201	12,366,306	3,047,183	21,972,826
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options	18						18
Issuance of common stock upon exercise of stock options (in Shares)						60,442
Stock-based compensation	248						248
Net loss	(1,501)							(1,501)
Ending balance at Sep. 30, 2020	(62,610)	$ 9,569	$ 14,083	$ 18,854	$ 4,682	$ 2	3,308	(65,920)
Ending balance (in shares) at Sep. 30, 2020		26,157,622	20,238,201	12,366,306	3,047,183	22,033,268
Beginning balance at Dec. 31, 2020	(68,009)	$ 9,569	$ 14,083	$ 18,854	$ 4,682	$ 2	3,707	(71,718)
Beginning balance (in shares) at Dec. 31, 2020		26,157,622	20,238,201	12,366,306	3,047,183	22,118,619
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options	244						244
Issuance of common stock upon exercise of stock options (in Shares)						367,432
Stock-based compensation	828						828
Net loss	(7,857)							(7,857)
Ending balance at Mar. 31, 2021	(74,794)	$ 9,569	$ 14,083	$ 18,854	$ 4,682	$ 2	4,779	(79,575)
Ending balance (in shares) at Mar. 31, 2021		26,157,622	20,238,201	12,366,306	3,047,183	22,486,051
Beginning balance at Dec. 31, 2020	$ (68,009)	$ 9,569	$ 14,083	$ 18,854	$ 4,682	$ 2	3,707	(71,718)
Beginning balance (in shares) at Dec. 31, 2020		26,157,622	20,238,201	12,366,306	3,047,183	22,118,619
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in Shares)	526,819
Net loss	$ (47,647)
Ending balance at Sep. 30, 2021	76,975					$ 11	196,330	(119,366)
Ending balance (in shares) at Sep. 30, 2021						112,818,724
Beginning balance at Mar. 31, 2021	(74,794)	$ 9,569	$ 14,083	$ 18,854	$ 4,682	$ 2	4,779	(79,575)
Beginning balance (in shares) at Mar. 31, 2021		26,157,622	20,238,201	12,366,306	3,047,183	22,486,051
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options	24						24
Issuance of common stock upon exercise of stock options (in Shares)						63,004
Stock-based compensation	785						785
Net loss	(5,335)							(5,335)
Ending balance at Jun. 30, 2021	(79,320)	$ 9,569	$ 14,083	$ 18,854	$ 4,682	$ 2	5,588	(84,910)
Ending balance (in shares) at Jun. 30, 2021		26,157,622	20,238,201	12,366,306	3,047,183	22,549,055
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of redeemable convertible preferred stock into common stock in connection with the reverse recapitalization (Note 2)	47,188	$ (9,569)	$ (14,083)	$ (18,854)	$ (4,682)	$ 6	47,182
Conversion of redeemable convertible preferred stock into common stock in connection with the reverse recapitalization (in shares)		(26,157,622)	(20,238,201)	(12,366,306)	(3,047,183)	61,809,312
Conversion of convertible promissory notes to common stock in connection with the reverse recapitalization (Note 6)	7,122					$ 1	7,121
Conversion of convertible promissory notes to common stock in connection with the reverse recapitalization (in Shares)						4,633,507
Beneficial conversion feature of convertible promissory notes in connection with the reverse recapitalization (Note 6)	26,061						26,061
Reverse recapitalization transaction, net of fees	101,035					$ 2	101,033
Reverse recapitalization transaction, net of fees (in Shares)						21,959,227
Conversion of preferred stock warrants and common stock warrants in connection with the reverse recapitalization (in shares)						1,771,231
Conversion of preferred stock warrants and common stock warrants in connection with the reverse recapitalization	8,571						8,571
Issuance of common stock upon exercise of stock options	77						77
Issuance of common stock upon exercise of stock options (in Shares)						96,392
Stock-based compensation	697						697
Net loss	(34,456)							(34,456)
Ending balance at Sep. 30, 2021	$ 76,975					$ 11	$ 196,330	$ (119,366)
Ending balance (in shares) at Sep. 30, 2021						112,818,724