I have a button in admin that invokes a URL (GET) like this:

/wp-admin/post.php?post=1545559&action=edit&bewpi_action=create&nonce=dbc6e6c4frd

It creates an invoice when pressed.

I have access to all variable values in this URL, so I can recreate it. I also have a function in functions.php that gets invoked when an order is paid and complete.

My question is, how can I invoke that URL (or the internal wordpress action) inside my function in functions.php?

Sorry if it’s a basic question. My googling skills failed me.