I have a form on wordpress page with a
I need to add an extra field to the form after submission but before it is sent to the URL in the action attribute.
I was thinking to use an actin hook, not sure which one would be the best for this case? or if it's the correct tool in the first place?
The form data is going to an e-banking service. the bank requires an extra field which is the hash value of all the variables concatenated together. the bank does the same operation when they receive a submission and compare with the extra field to ensure data integrity.