help me please! I want to attach paypal tracker code with wix button

i designed the wix form and connected to the database ,i want that when user clicks the submit button the data should be stored in the database and a paypal subcription should open

i did that by attaching the link which open after clicking the tracker code button ,to the wix button
but it opens into paypal homepage rather than into my subsrciption page.

NOW I WANT TO THAT WHEN USER CLICK ON THE SUBMIT BUTTONS IT SHOULD GOES TO THE SUBSCRITION PAGE BY ATTACHING THE FOLLOWING CODE TO WIX BUTTON

PLEASE HELP ME OUT

here is the code of the paypal tracker

Hi,
you can learn how to add such custom code to your site here .

the link you provided is for the Iframe where can past our code . What my question is how to connect the code in the Iframe with Wix button