FORM 3853 Has errors, won't submit my tax return electronically

I have already paid to submit my taxes to California. It won't submit because it says on FORM 3853 that the exemption certificate is blank. I am requesting an exemption due to a hardship for health insurance for 2020.

So, I do not have an exemption certificate number. I followed instructions on the form. It says to fill in an exemption number OR select 'pending' or 'NO ECN'. I have selected 'NO ECN', so I should not have to fill in an exemption number. However, it still comes up as an error and won't submit without typing an exemption certificate number.