CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net loss	$ (59,351)	$ (58,763)	$ (15,572)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation, amortization, and abandonment costs	2,412	7,677	4,490
Stock-based compensation expenses	17,065	5,114	2,322
Amortization of deferred contract acquisition and fulfillment costs	8,075	4,231	3,290
Change in valuation of warrants to purchase preferred and common stock	15,046	41,505	5,300
Non-cash interest expenses	331	263	407
Non-cash expenses with respect to stockholders’ loans	882	0	0
Gain on sale of property and equipment	(757)	0	0
Changes in operating assets and liabilities:
Decrease (increase) in trade receivables	(1,057)	(6,274)	6,159
Increase in prepaid expenses and other current assets and other assets, noncurrent	(2,299)	(864)	(54)
Increase in deferred contract acquisition and fulfillment costs	(18,051)	(12,947)	(6,590)
Increase in trade payables	3,886	2,064	2,004
Increase (decrease) in accrued expenses and other current liabilities	3,756	4,964	(1,517)
Increase in employees and payroll accruals	2,352	5,886	1,435
Increase (decrease) in other liabilities, noncurrent	(675)	635	39
Increase (decrease) in deferred revenue	6,275	12,313	(1,343)
Net cash provided by (used in) operating activities	(22,110)	5,804	370
Cash flows from investing activities:
Net cash acquired in business combination	0	383	0
Purchases of property and equipment	(1,876)	(1,118)	(2,239)
Proceeds from sale of property and equipment	757	0	0
Capitalized internal-use software development costs	(3,978)	(1,849)	(249)
Purchase of intangible assets	(145)	(162)	(244)
Net cash used in investing activities	(5,242)	(2,746)	(2,732)
Cash flows from financing activities:
Proceeds from initial public offering, net of underwriting discounts and commissions	160,425	0	0
Payment related to the conversion of Series F redeemable convertible preferred stock upon initial public offering	(1,569)	0	0
Proceeds from long-term loans, net of debt issuance cost	41,915	2,000	2,971
Repayment of long-term loans	(51,833)	(1,667)	0
Principal payments on finance leases	(1,717)	(2,354)	(2,818)
Proceeds from exercise of stock options	1,335	280	147
Payment of deferred offering costs	(5,188)	(106)	0
Net cash provided by (used in) financing activities	143,368	(1,847)	300
Net increase (decrease) in cash, cash equivalents and restricted cash	116,016	1,211	(2,062)
Cash, cash equivalents and restricted cash at the beginning of the year	28,355	27,144	29,206
Cash, cash equivalents and restricted cash at the end of the year	144,371	28,355	27,144
Supplemental disclosure of non-cash activity:
Purchase of property, equipment, internal-use software, and intangible asset in credit	1,106	155	142
Purchase of property and equipment by capital lease	0	0	98
Conversion of warrants to common stock upon initial public offering	70,677	0	0
Conversion of convertible and redeemable convertible preferred stock to common stock upon initial public offering	161,261	0	0
Issuance of ordinary shares and warrant with respect to business combination	0	3,799	0
Unpaid deferred offering costs	0	976	0
Supplemental disclosure of cash flow information
Cash paid for income taxes, net	2,636	1,210	1,073
Cash paid for interest	1,944	3,947	4,298
Reconciliation of cash, cash equivalents, and restricted cash to the consolidated balance sheet
Cash and cash equivalents	143,949	27,711	26,538
Restricted cash included in other assets, non-current	422	644	606
Total cash, cash equivalents, and restricted cash	$ 144,371	$ 28,355	$ 27,144