@MarwanRashwan I experienced the same problem on debian - this seems to be happening because honcho (process manager) is installed in the pipx environment but the .../bin/ folder which contains the honcho executable is not on the PATH.
I was able to fix this locally by updating the PATH environment variable to include the .../bin/ folder - in you case, you will likely have to add /home/marwan/.local/share/pipx/venvs/frappe-bench/bin/honcho ← do double-check this path.