No, there is no way to do that. You cannot access PHP from a form.
A form is an HTML element rendered on a page in a browser on the user’s machine. It doesn’t live on your server, but with the user.
The only way a form (or anything else on the user’s machine) has to communicate with your server is to send a request, generally an HTTP request. A request needs an endpoint, which is a URL. You cannot directly access some random piece of code on your server from the user’s browser. In Laravel, the way to specify a URL for a form to call is by using routes.
If you think you need to access a method in a controller directly you should think about abstracting them to a Service class (or something similar) and then defer your controller to use that service class instead.