When running first_time_setup.sh

[EdvinCode]

error: externally-managed-environment

× This environment is externally managed
╰─> To install Python packages system-wide, try apt install
python3-xyz, where xyz is the package you are trying to
install.

If you wish to install a non-Debian-packaged Python package,
create a virtual environment using python3 -m venv path/to/venv.
Then use path/to/venv/bin/python and path/to/venv/bin/pip. Make
sure you have python3-full installed.

For more information visit http://rptl.io/venv

note: If you believe this is a mistake, please contact your Python installation or OS distribution provider. You can override this, at the risk of breaking your Python installation or OS, by passing --break-system-packages.
hint: See PEP 668 for the detailed specification.
By default, the RVR SDK uses the UART on /dev/ttys0 to communicate with RVR.
Do you have Serial Port enabled and Serial Shell disabled in Raspberry Pi Configuration?

[rudraforweb]

Use nano or whatever you use to edit files, go to first-time-setup.sh, and then remove pip3 install --user -r requirements.txt and replace with pip3 install --user --break-system-packages -r requirements.txt.

This solved the same thing that happened to me.

[rudraforweb]

I just realized, the answer was in your post!
note: If you believe this is a mistake, please contact your Python installation or OS distribution provider. You can override this, at the risk of breaking your Python installation or OS, by passing --break-system-packages.
LOL