| In millions, except per share items | Jun-30-23 | Mar-31-23 | Dec-31-22 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 |
| | 10-Q | 8-K | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q |
| Revenue | 40.2 | 44.4 | 42.7 | 60.3 | 71.8 | 93.4 | 104.9 | 102.1 |
| Revenue growth | -44.0% | -52.5% | -59.3% | -41.0% | -19.8% | 11.7% | 54.9% | 70.2% |
| Costs and expenses: | | | | | | | | |
| Cost of revenue | 3.7 | 13.5 | 4.9 | 7.6 | 9.0 | 9.3 | 9.0 | 7.6 |
| Research and development | 9.0 | | 6.7 | 8.4 | 18.3 | 18.7 | 15.6 | 13.2 |
| Sales and marketing | 33.1 | 34.9 | 34.7 | 51.8 | 73.7 | 117.3 | 156.3 | 114.5 |
| General and administrative | 30.1 | 28.1 | 23.2 | 20.3 | 26.9 | 92.8 | 34.7 | 48.4 |
| Total costs and expenses | 75.8 | 76.5 | 190.0 | 135.5 | 127.9 | 238.0 | 215.6 | 183.7 |
| Loss from operations | -35.6 | -32.1 | -147.4 | -75.3 | -56.1 | -144.6 | -110.7 | -81.6 |
| Operating margin | -88.7% | -72.3% | -345.2% | -124.9% | -78.2% | -154.8% | -105.5% | -80.0% |
| Gain on extinguishment of debt | 15.2 | | | | | | | |
| Interest expense, net | -1.7 | -3.5 | -4.4 | -3.8 | -7.6 | -8.2 | -1.1 | -0.1 |
| Change in fair value of common stock warrant liabilities | 0.2 | | 0.6 | -0.1 | 1.0 | 4.5 | 6.0 | 113.6 |
| Other income (expense), net | 0.0 | | -0.3 | 0.5 | -0.1 | 0.0 | -0.1 | 0.0 |
| Loss before income taxes | -22.0 | | -151.5 | -78.7 | -62.8 | -148.3 | -105.8 | 31.8 |
| Provision for (benefit from) income taxes | 0.0 | 0.1 | 0.1 | -0.1 | -0.2 | -0.2 | -0.3 | -18.9 |
| Net loss | -22.0 | -35.6 | -151.6 | -78.5 | -62.6 | -148.1 | -105.5 | 50.8 |
| |
| Net loss per share attributable to common stockholders: | | | | | | | | |
| Basic (in dollars per share) | ($1.05) | | ($0.37) | ($0.19) | ($3.07) | ($0.37) | ($0.27) | $0.13 |
| Diluted (in dollars per share) | ($1.05) | | ($0.37) | ($0.19) | ($3.07) | ($0.37) | ($0.28) | ($0.16) |
| |
| Weighted average shares outstanding: | | | | | | | | |
| Basic (in shares) | 21.0 | | 410.0 | 413.8 | 20.4 | 401.7 | 384.6 | 395.1 |
| Diluted (in shares) | 21.0 | | 410.0 | 413.8 | 20.4 | 401.7 | 388.5 | 396.0 |
| |
| Other comprehensive income (loss): | | | | | | | | |
| Change in unrealized loss on available-for-sale investments, net of tax | 0.4 | | -1.3 | | -0.6 | | -0.2 | |
| Total other comprehensive income (loss): | 0.4 | | 1.2 | 0.1 | -0.6 | -2.0 | -0.2 | |
| Total comprehensive loss | -21.6 | -34.6 | -150.4 | -78.4 | -63.2 | -150.2 | -105.8 | 50.8 |