Expense rule / sheets custom fields

Hello,

I have a requirement to add a checkbox in expense rule called price_unit_eligiblity (SCREEN 1)

when it’s not checked ,two other fields in expense sheet should be disabled  (SCREEN 2)

I’ve added all the custom fields , but I don’t know how to disable the 2 columns based on the condition mentionned .

Thank you in advance,

Hanane