Twitter was an expensive deal for Musk to take over the media platform. The first set of interest payments on the loans he took to acquire twitter was from I heard $1billion to his lenders.
https://fortune.com/2023/01/18/elon-musk-twitter-sales-revenue-interest-payment-loans-debt

My guess would be selling more stock of his other companies or possibly his holdings in bitcoin to offset the next set of interest payments in a couple of months.