I changed the original Dockerfile, because in UV documentation the Dockerfile looks this, but I guess the bin folder only applies to IOs, and for windows its called Scripts, so I changed lines 4 and 14 from /bin to /Scripts (I don't think that's the problem)

That is absolutely the problem.

You're not running in a Windows container; you're running a Linux container. The default $PATH (the variable in which the system will search for unqualified binary names like uv) typically includes /bin, but it does not include /Scripts.

By placing the uv binary in /Scripts, you have placed it where it won't be found.

• You could add /Scripts to your $PATH, and then you could run uv and it would work.
• You could call it with a fully qualified path, like /Scripts/uv.

But the easiest solution is to not makes changes just for the sake of changing things: put the binaries in /bin as documented and they will work as expected.

With the following Dockerfile, everything works as expected:

FROM python:3.11

# Install uv.
COPY --from=ghcr.io/astral-sh/uv:latest /uv /uvx /bin/

# Copy the application into the container.
COPY . /app

# Install the application dependencies.
WORKDIR /app
RUN uv sync --frozen --no-cache

# Run the application.
CMD ["/app/.venv/bin/uvicorn", "src.main:app", "--port", "80", "--host", "0.0.0.0"]