Laravel App Error – Failed to open stream: No such file or directory

I just got this project assigned to me, and I am still learning Laravel Framework, however, this app started to show this error message like a week ago, before that it would render the home page and would work, not entirely, but it would render the views. I did not change anything in the code, just tried to sign up as a normal user to test it in the browser like anyone would so it is very confusing to me what is going on… I honestly can´t seem to fully understand the whole structure of this app that someone else was working on before, but I was hoping someone would come and help me out.

I share screenshots of the error and also a link for a detailed view:

https://flareapp.io/share/NPLxQo4P

I have access to the cPanel where the app is hosted, but I just don´t want to change anything just yet. This app is a talent recuitment app, and it was developed by a freelancer programmer who I believe nevere really finished it, however I can confirm it was explorable and was correctly rendering the majority of the views. Now you cant even see a render, the domain just keeps throwing the error for everyone.

I’ve seen the recommendations of composer dumpaoutoload but I am not sure if I should do it.

Also, I saw that in the routes web.php the class is being called like this:

use AppHttpControllersActivitiesSignupController; 

However below it is being used like this:

    // Route::get('/talentsignup', [signupController::class, 'talentsignup'])->name('talentsignup');
    // Route::get('/crewsignup', [signupController::class, 'crewsignup'])->name('crewsignup');
    Route::get('/signup', [signupController::class, 'signup'])->name('signup');
    Route::get('/submitproject', [ProjectsController::class, 'submitproject'])->name('submitproject');

it differs in the capital "S" of "signupController::class" rather than the "SignupController" in the "use" is that even supposed to mean something? I am so confused.