Statements of cash flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net loss	$ (17,837)	$ (10,444)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	755	615
Share-based compensation	621	14
Change in fair value of warrant liability	5,538
Deferred rent	(2)	3
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(2,411)	(53)
Accounts payable	504	75
Accrued expenses and other current liabilities	698	190
Net cash used in operating activities	(12,134)	(9,600)
Cash flows from investing activities:
Purchases of property and equipment	(586)	(233)
Net cash used in investing activities	(586)	(233)
Cash flows from financing activities:
Proceeds from convertible promissory notes		6,800
Proceeds from exercise of stock options	20	5
Proceeds from long-term debt	500
Proceeds from the sale of common stock in connection with IPO	44,850
Payment of IPO costs	(5,973)
Proceeds from the sale of Series A convertible preferred stock	11,046	4,616
Payment of Series A convertible preferred stock issuance costs	(49)	(35)
Payment of equipment loan payable	(212)	(225)
Payment of capital lease obligations	(239)	(387)
Net cash provided by (used in) financing activities	49,943	10,774
Net increase (decrease) in cash and restricted cash	37,223	941
Cash and restricted cash at beginning of year	2,643	1,702
Cash and restricted cash at end of year	39,866	2,643
Supplemental disclosures of cash flow information:
Cash paid for interest	29	106
Supplemental disclosures of non-cash investing and financing activities:
Conversion of Series A convertible preferred stock upon IPO	48,369
IPO costs included in accounts payable	135
Fair value of liability-classified warrants issued in connection with Series A convertible preferred stock	1,522
Conversion of liability-classified warrants upon IPO	$ 7,060
Issuance of Series A convertible preferred stock upon conversion of convertible promissory notes		$ 6,800