register a Advanced Custom Fields Repeater having Number and URL sub fields on an Options page using ACF Pro
use Gravity Forms' gform_confirmation filter to set up conditional redirect to the URL corresponding to the submitted number by looping through the repeater's rows
for setting up a dynamic system wherein the site owner can enter numbers and corresponding URLs in the Options page so that when a visitor inputs a number and submits the Gravity Forms form, they will be redirected to different URLs depending on the number entered as set in the Options page.
Step 1
Let us first create a simple form with a single Number field and set up static conditional redirects. After that, we will add ACF Pro and make it dynamic.