Missing 2020 Form 6251

While using 2021 Turbo Tax Home & Business, it asks the user to verify that Line 4 of 2020 Form 6251 is correct. Although I also used 2020 Turbo Tax Home & Business, and saved the available records, worksheets, forms, etc. as PDFs, there was no trace of a 2020 Form 6251 in any of them. On this same page, is a blue link "What if I don't have Form 6251?", with a lot of gobbledygook, ending with "If you don't know your AMTI, most people will get the same result using your "regular" taxable income (2020 Form 1040, 10)." However, 2020 Form 1040, Line 10 is nonexistent. Although there are Lines 10a, 10b, 10c, they are NOT "Taxable Income". Taxable Income is Line 15 - but even then, it is not the same as the AMT (worse, it is off by tens of thousands from the amount they are wanting me to verify)! What is the user to do? How much more can Turbo Tax screw this up? Eventually, I re-installed 2020 Home & Business, and searched and found Form 6251, and saved it by clicking "Forms" in top-right, then, and saved as a PDF. However, it does not appear in any of the PDFs that you would normally save using the various options available to save forms, worksheets, etc. Is this really what is expected of the user - to spend extra hours finding workarounds for Turbo Tax's shortcomings?