How can I change "action" from the iframe code?

Hi,

I wont to change the "action" to send the form by post to our PHP page and then to the DB.

(i used your iframe option)

how can I change it?

It is possible to set up the form so it POSTed submissions. Please check related guides below:

How-to-Post-Submission-Data-to-Thank-You-Page

How-to-send-Submissions-to-Your-MySQL-Database-Using-PHP

Let us know if you need more help.