Why can I not enter either a number or supporting evidence for prescription mediicine deductions

[lingpong]

Turbotax 2019 Premier does not let me enter a number in prescription medicine co-payment field or allow me to itemize in the supporting evidence format. 

I also had the same problem in one of the input panels in the income section.

[JotikaT2]

Try the following:

Go the Federal Taxes tab and select Deductions & Credits.

Select I'll choose what I work on.

Scroll down to Medical, Medical Expenses.

You should see the following screen but with a different amount listed. 

Based on how you answered this question, it may affect your ability to enter information.  If you would like to enter expenses, select Yes and you will be able to proceed with the detailed input.