My setup details

Python folder C:\progs\python
>python --version
Python 3.13.5

I didn't had pip installed in python folder. A work around was to use

py -m pip

>py -m pip list
Package Version
------- -------
pip     25.1.1

Install dependencies

py -m pip install fastapi uvicorn transformers torch

Start API

py -m uvicorn main:app --reload

Test it at

http://localhost:8000/docs