Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net loss before noncontrolling interest	$ (5,942)	$ (7,165)
Adjustments to reconcile net loss before noncontrolling interest to net cash used in operating activities:
Depreciation expense	23	27
Share-based compensation expense	436	380
Change in fair value of warrants, related party	1,648	363
Amortization of debt discount		47
Changes in assets and liabilities:
Accounts receivable	156
Prepaid expenses and other assets	540	465
Accounts payable and accrued expenses	(1,173)	331
Contract liabilities	(987)	(8)
Net cash used in operating activities	(5,299)	(5,560)
Cash flows from financing activities:
Proceeds from issuance of Class A Common Stock to a related party under the Letter Agreements		6,000
Proceeds from issuance of Class A Common Stock, net of offering costs	8,038
Proceeds from exercise of stock options	47
Repayment of notes payable	(84)	(1,811)
Net cash provided by financing activities	8,001	4,189
Net increase (decrease) in cash, cash equivalents and restricted cash and cash equivalents	2,702	(1,371)
Total cash, cash equivalents and restricted cash and cash equivalents, beginning of period	5,747	4,277
Total cash, cash equivalents and restricted cash and cash equivalents, end of period	8,449	2,906
Non-cash activities:
Change in redemption value of noncontrolling interest	19,547	(14,454)
Redeemable Noncontrolling Interest [Member]
Non-cash activities:
Change in redemption value of noncontrolling interest	$ (19,547)	$ 14,454