Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating Activities
Net loss	$ (14,536)	$ (22,438)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	515	1,026
Depreciation and amortization	113	45
Bad debt expense	200
Changes in operating assets and liabilities:
Accounts receivable	1,054	2,307
Prepaid and other current assets	1,485	(1,671)
Accounts payable	(1,713)	(2,969)
Accrued compensation and other accrued liabilities	1,036	(31)
Operating lease liability and right-of-use asset	26	26
Deferred revenue	(230)	(651)
Net cash flows used in operating activities	(12,050)	(24,356)
Investing Activities
Proceeds from maturities of short-term investments	2,504	27,581
Net cash flows provided by investing activities	2,504	27,581
Financing Activities
Issuance of common stock for public offering, net of issuance costs		49,277
Issuance of common stock from stock grants	16	182
Net cash flows provided by financing activities	16	49,459
Net increase (decrease) in cash and cash equivalents	(9,530)	52,684
Cash and cash equivalents at beginning of the period	44,347	30,360
Cash and cash equivalents at end of the period	$ 34,817	$ 83,044