CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Revenue	$ 4,312	$ 4,192	$ 9,265
Cost of revenue	10,198	8,447	5,833
Gross profit (loss)	(5,886)	(4,255)	3,432
Research and development expenses	102,503	109,587	74,768
General and administrative expenses	31,761	31,070	28,407
Selling and marketing expenses	7,638	7,043	4,443
Total operating expenses	141,902	147,700	107,618
Operating loss	(147,788)	(151,955)	(104,186)
Interest income	8,925	3,707	372
Other income (expense), net	(10,470)	943	1,936
Net loss before income taxes	(149,333)	(147,305)	(101,878)
Income taxes provision	0	0	0
Net loss	(149,333)	(147,305)	(101,878)
Unrealized gain (loss) on available-for-sale securities	3,498	(3,061)	(524)
Total comprehensive loss	$ (145,835)	$ (150,366)	$ (102,402)
Net loss per share, basic	$ (0.66)	$ (0.68)	$ (0.51)
Net loss per share, diluted	$ (0.66)	$ (0.68)	$ (0.51)
Weighted-average shares used in computing net loss per share, basic	227,060,773	217,307,896	200,849,663
Weighted-average shares used in computing net loss per share, diluted	227,060,773	217,307,896	200,849,663