Want to audit the views like iby_ext_bank_branches_v,iby_ext_banks_v

For any change in banks or bank branches i want to audit that details in my custom table.

For that i have written instead of trigger on both above mentioned view but if i create or update any record in banks from front end , the trigger is not getting called.

How to call trigger written on view ? or

When the instead of triggers are called ?

Please advice. It's very urgent.