Depends on the terms but there will be provisions to allow conversion into equity.
Discussion
Terms of their $600m note offering from earlier in the year are here: https://www.microstrategy.com/press/microstrategy-completes-603-million-offering-of-0875-convertible-senior-notes-due-2031_03-19-2024
It’s very wordy but basically MicroStrategy pays $5m in interest per annum for 7 years and then can repay them in cash prior to the 2031 maturity date. Otherwise they convert at an effective price of $2.3k per share.