You cannot amend your filing status from married filing jointly to married filing separately after the due date of the tax return, which has now passed for both 2023 and 2024.
The only exception to that rule is if your joint tax return was invalid because you were not actually married at the end of the tax year. If that is your situation, correcting it is very complicated and requires the assistance of a tax professional who is familiar with the procedure. If you just file an amended return changing the filing status the IRS will reject it.
