Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities
Net income (loss)	$ 28,778	$ (24,597)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	351	207
Amortization of premiums and discounts on marketable securities	1	14
Non-cash lease expense	293	272
(Gain) on disposal of property and equipment	(147)	0
Stock-based compensation expense	2,753	1,780
Non-cash interest expense	383	387
Warrant liabilities revaluation	(18,515)	16,747
Changes in operating assets and liabilities:
Accounts receivable	2,761	(1,118)
Prepaid expenses, deposits and other assets	853	(1,512)
Accounts payable	18	151
Income taxes payable	(281)	0
Deferred revenue	(26,890)	(2,728)
Accrued expenses and other liabilities	(2,222)	(1,736)
Net cash (used in) operating activities	(11,864)	(12,133)
Cash flows from investing activities
Proceeds from maturities of marketable securities	10,000	0
Purchases of marketable securities	0	(22,420)
Purchases of property and equipment	(455)	(25)
Net cash provided by (used in) investing activities	9,545	(22,445)
Cash flows from financing activities
Debt amendment fee included in Debt Discount	(110)	0
Net proceeds from issuance of common stock	1,690	20,991
Proceeds from exercise of stock options	21	244
Proceeds from issuance of common stock under Employee Stock Purchase Plan	127	72
Net cash provided by financing activities	1,728	21,307
Effect of exchange rate changes on cash	(29)	(7)
Net change in cash, cash equivalents, and restricted cash	(620)	(13,278)
Cash, cash equivalents, and restricted cash at beginning of period	115,436	140,064
Cash, cash equivalents, and restricted cash at end of period	114,816	126,786
Supplemental cash flow information
Cash paid for interest	494	494
Noncash investing and financing activities
Purchase of property and equipment not yet paid	91	10
Equity offering costs in accrued liabilities	$ 94	$ 48