Stripe callback url after routes.yaml modification

Hello everyone,
I have updated the file routes.yaml with new routes for membership endpoints and have changed the name of the handlebars files, so they are rendering well. The problem is that I want to update the callback url for Stripe when a payment is confirmed, because it redirects me to the previous route, it’s not updated with the new route I have defined and it appears a 404. I have thought to create a redirect through redirects file, but is there a better option?
Also, I would like to know if it’s feasible to change the code located in /var/www/ghost/current or this would be updated as soon as another ghost version is released? What if I want to change these files to customize the logic behind ghost?