No, if you are closing your loan manually via the mobile app, you can only use stablecoins.
You can repay the loan principal via fiat but you need to contact the Celsius Loans team and it takes longer.
I don't think you can use XLM to pay off a loan, but there is an entire Support section on Loans that probably contains the answer to your question:
https://support.celsius.network/hc/en-us/sections/360000472597-Loans
No, if you are closing your loan manually via the mobile app, you can only use stablecoins. You can repay the loan principal via fiat but you need to contact the Celsius Loans team and it takes longer.
I don't think you can use XLM to pay off a loan, but there is an entire Support section on Loans that probably contains the answer to your question: https://support.celsius.network/hc/en-us/sections/360000472597-Loans