I have a need for website B to grab a form from website A and post the form data to a process on website A. Site A is the 'keeper of data submitted', and site B is an approved client of A that is authorized to collect data on their site B to send to A.
Sample scenario: website B contains a database of clients. Website B (many different sites) need to have a form from website A displayed on their site (B). That form's content needs to be submitted to A (with proper sanitation). The form from A is unique to B, so that site C (and others) can use the same form. The form has a hidden unique GUID field supplied by A when B requests
The form is like a signup form (name, email) for a service that A provides. The form needs to display on B (or other sites) with the data submitted/processed by A.
Some JS code would be inserted on B to display the form from A. Site A has code to process the data that B posts (submits) to A.
Flow would be
B requests a form from A via some process (JS?) that loads the A form on B's page load. A creates the form plus a unique hidden field B shows the form on a page on the B site. B fills the form, and submits to A (action = A) A receives the posted data from B, and process it A's processing status (pass/fail) is returned to B
Assume that the returned form data submitted by B is sanitized by A.
But I am sure there is guidance 'out there' - my searching has not found anything helpful yet.