When I try to use the default docs in FastApi never works. If I use /docs it gives an error saying:

"Failed to load API definition. Error Hide Fetch Internal Server Error /openapi.json"

and if I use /redoc it loads forever and never appears anything. I searched a lot but the only thing I found out was someone using root_pah="/folder/" inside of the FastAPI() main instance, so I used the app folder which is the repository of the whole api project. I don't know if it will help you guys but the tree of the project is:

C:.
├───.pytest_cache
│   └───v
│       └───cache
├───alembic
├───app
│   ├───models
│   │   └───__pycache__
│   ├───routers
│   │   └───__pycache__
│   ├───tests
│   │   ├───.pytest_cache
│   │   │   └───v
│   │   │       └───cache
│   │   └───__pycache__
│   └───__pycache__
├───venv
│   ├───Include
│   │  
│   └───Scripts
└───__pycache__

p.s. I wiped most of the part of the venv directory because I thought that it was useless for this and also when I tried to copy and paste the whole output in here, Stack Overflow would accept just part of it because it was too big.