Bitwarden has its own script to manage the containers. It’s not your typical self hosted app docker installation. What OP is looking for is easily accessible in their FAQ section of the documentation.
Q: How do I use custom server ports?
A: To use custom ports, instead of 80 and 443, edit the http_port= and https_port= values in ./bwdata/config.yml and run ./bitwarden.sh rebuild to rebuild your server assets.
Check that the custom port values have been proliferated to ./bwdata/env/global.override.env.