To adjust the port used you need to modify the port in data/tinyproxy.conf and adjust the ports in docker-compose.yml
You can of course also only modify the port mapping.
To start:
docker compose up
If your source IP gets blocked by tinyproxy check the log for the error message, adjust the Allow statement in the tinyproxy.conf
For example in the logs you see 172.17.0.1 is blocked, just add another
Allow 172.17.0.1
to the config.