subfolder request redirects to 8080

Hello,
I have deployed standard Laravel app and when I request subfolder I am getting redirected to port 8080: https://shy-haze-9357.fly.dev/sl redirects to https://shy-haze-9357.fly.dev:8080/sl/. How could this be fixed? What I eventually need is going to https://shy-haze-9357.fly.dev/sl /index.php when I request subfolder.
Thanks
Tadek