WooCommerce Software Add-on API wp_remote_get

Can anyone help me understand how to submit the wp_remote_get via a form.

For example, I’m using the WooCommerce Software Add-on Extension (WordPress Plugin) and I have to use wp_remote_get to send a call to the server from wherever *my* custom Plugin is installed to validate the serial. But I don’t know how to send that call. Just post to a PHP file with that function in it?

Thanks!