Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders (Deficit) Equity (Unaudited) - USD ($) $ in Thousands	Total	Convertible Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning balance at Dec. 31, 2019	$ (19,723)			$ 1,364		$ (21,087)
Temporary equity, beginning balance, shares at Dec. 31, 2019		2,617,386
Temporary equity, beginning balance at Dec. 31, 2019		$ 17,051
Beginning balance, shares at Dec. 31, 2019			3,641,449
Issuance of common stock upon exercise of common stock options	176			176
Issuance of common stock upon exercise of common stock options, shares			220,043
Stock-based compensation	58			58
Net loss	(1,805)					(1,805)
Ending balance at Mar. 31, 2020	(21,294)			1,598		(22,892)
Temporary equity, ending balance, shares at Mar. 31, 2020		2,617,386
Temporary equity, ending balance at Mar. 31, 2020		$ 17,051
Ending balance, shares at Mar. 31, 2020			3,861,492
Beginning balance at Dec. 31, 2019	(19,723)			1,364		(21,087)
Temporary equity, beginning balance, shares at Dec. 31, 2019		2,617,386
Temporary equity, beginning balance at Dec. 31, 2019		$ 17,051
Beginning balance, shares at Dec. 31, 2019			3,641,449
Net loss	(3,797)
Ending balance at Jun. 30, 2020	(12,529)			12,355		(24,884)
Temporary equity, ending balance, shares at Jun. 30, 2020		12,503,009
Temporary equity, ending balance at Jun. 30, 2020		$ 92,357
Ending balance, shares at Jun. 30, 2020			4,607,565
Beginning balance at Mar. 31, 2020	(21,294)			1,598		(22,892)
Temporary equity, beginning balance, shares at Mar. 31, 2020		2,617,386
Temporary equity, beginning balance at Mar. 31, 2020		$ 17,051
Beginning balance, shares at Mar. 31, 2020			3,861,492
Issuance of common stock upon exercise of common stock options	62			62
Issuance of common stock upon exercise of common stock options, shares			58,006
Issuance of Series B convertible preferred stock and common stock warrants, net of issuance costs of $3.5 million	10,591			10,591
Temporary Equity, Issuance of Series B convertible preferred stock and common stock warrants, net, shares		9,372,765
Temporary Equity, Issuance of Series B convertible preferred stock and common stock warrants, net		$ 70,791
Temporary Equity, Issuance of the Series B-1 convertible preferred stock upon conversion of convertible notes, shares		512,858
Temporary Equity, Issuance of the Series B-1 convertible preferred stock upon conversion of convertible notes		$ 4,515
Exercise of common stock warrants	55			55
Exercise of common stock warrants, shares			688,067
Stock-based compensation	49			49
Net loss	(1,992)					(1,992)
Ending balance at Jun. 30, 2020	(12,529)			12,355		(24,884)
Temporary equity, ending balance, shares at Jun. 30, 2020		12,503,009
Temporary equity, ending balance at Jun. 30, 2020		$ 92,357
Ending balance, shares at Jun. 30, 2020			4,607,565
Beginning balance at Dec. 31, 2020	274,282		$ 3	315,288	$ 33	(41,042)
Beginning balance, shares at Dec. 31, 2020			32,485,784
Issuance of common stock upon exercise of common stock options and vesting of restricted stock units	70			70
Issuance of common stock upon exercise of common stock options and vesting of restricted stock units, Shares			64,527
Proceeds from follow-on public offering, net of underwriters' discounts and commissions and issuance costs	96,762		$ 1	96,761
Proceeds from follow-on public offering, net of underwriters' discounts and commissions and issuance costs, Shares			4,600,000
Stock-based compensation	974			974
Other comprehensive income	(5)				(5)
Net loss	(8,866)					(8,866)
Ending balance at Mar. 31, 2021	363,217		$ 4	413,093	28	(49,908)
Ending balance, shares at Mar. 31, 2021			37,150,311
Beginning balance at Dec. 31, 2020	$ 274,282		$ 3	315,288	33	(41,042)
Beginning balance, shares at Dec. 31, 2020			32,485,784
Issuance of common stock upon exercise of common stock options, shares	148,544
Issuance of common stock under employee stock purchase plan, shares			15,867
Net loss	$ (22,840)
Ending balance at Jun. 30, 2021	350,709		$ 4	414,550	37	(63,882)
Ending balance, shares at Jun. 30, 2021			37,251,771
Beginning balance at Mar. 31, 2021	363,217		$ 4	413,093	28	(49,908)
Beginning balance, shares at Mar. 31, 2021			37,150,311
Issuance of common stock upon exercise of common stock options	119			119
Issuance of common stock upon exercise of common stock options, shares			85,593
Issuance of common stock under employee stock purchase plan	229			229
Issuance of common stock under employee stock purchase plan, shares			15,867
Stock-based compensation	1,109			1,109
Other comprehensive income	9				9
Net loss	(13,974)					(13,974)
Ending balance at Jun. 30, 2021	$ 350,709		$ 4	$ 414,550	$ 37	$ (63,882)
Ending balance, shares at Jun. 30, 2021			37,251,771