You might try e-filing a "superceding" return when you have the data, either by 4/15 or by 10/15 if the return was extended. The last return filed by the due date (original or extended) is considered the  original return.

I don't think you need to file an amended return unless the return changes after the due date (original or extended). Lacerte has an article on how to file a superceding return.

https://accountants.intuit.com/support/en-us/help-article/corporation/e-filing-superseded-returns-la...