I’m building a URL shortener with FastAPI, and I’m running into a problem with redirects. When I try to redirect users, I get this error:

Failed to fetch.
Possible Reasons:
CORS
Network Failure
URL scheme must be “http” or “https” for CORS request.

Here’s the code for the redirect function:

from fastapi import FastAPI, HTTPException
from fastapi.responses import RedirectResponse

@link.get("/{url}")
async def redirect(db: db_dependency, url: str):
    original_url_record = db.query(Urls).filter(Urls.short_url == url).first()
    if original_url_record:
        original_url = original_url_record.original_url
        print(original_url)
        return RedirectResponse(url=original_url)
    else:
        raise HTTPException(status_code=404, detail="URL not found")

from fastapi.middleware.cors import CORSMiddleware

app = FastAPI()

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

I also allowed all origins in the CORS configuration and ensured original_url starts with “http://” or “https://” but it didn’t helped

How do I redirect user to another url conventionally and what themes I should be familliar to not make this mistakes?