Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net loss	$ (34,425)	$ (18,320)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	2,186	834
Stock-based compensation	1,732	365
Changes in current assets and liabilities:
Prepaid expenses and other assets	(3,037)	(189)
Right-of-use assets and lease liabilities, net	20	386
Accounts payable	2,472	1,071
Accrued expense and other liabilities	1,387	373
Deferred revenue	(4,632)	19,807
Net cash used in operating activities	(34,297)	4,327
Cash flows from investing activities:
Purchases of property and equipment	(7,730)	(2,853)
Net cash used in investing activities	(7,730)	(2,853)
Cash flows from financing activities:
Proceeds from issuance of convertible preferred stock, net of issuance costs	99,730
Proceeds from exercise of stock options	171	248
Proceeds from initial public offering, net of issuance costs	89,647
Net cash provided by financing activities	189,548	248
Net increase (decrease) in cash, cash equivalents and restricted cash	147,521	1,722
Cash, cash equivalents, and restricted cash - beginning of period	35,386	42,359
Cash, cash equivalents, and restricted cash - end of period	182,907	44,081
Supplemental cash flow information:
Purchase of property and equipment in accounts payable and accrued liabilities	1,427	$ 458
Conversion of convertible preferred stock to common stock upon closing of initial public offering	$ 159,411