Here are the instructions to prepare and Efile an extension

https://proconnect.intuit.com/community/electronic-filing/help/filing-an-individual-extension-form-4...

Everything was completed as outlined - Federal First Extension (returns to electronically file) - Extension (EF type) - Completed (status) in box to choose tax returns, extensions to file electronically.  It won't let me "check" Federal First Extension!! 😞

Thanks for any help/suggestions you can give me.

I guess I dont understand what you mean by "check"...go to the EFCenter, and highlight the file, click the EFNow button on the toolbar, choose Convert and click OK...does it convert for Efiling or does it fail conversion?

I am having the same problem.  Where is Intuit when you need them?