api/signup could not be found

[meakcey]

I have followed the youtube tutorial from beginning and stucked on the same error
POST http://localhost:3000/$%7Bimport.meta.env.VITE_API_BASE_URL%7D/api/signup 404 (Not Found)
Signup.jsx

I have executed this repo also having similar error
"message": "The route api/signup could not be found.",

I am newbie and could figure out how to solve