This Gist is about how to setup TiddlyWiki behind an Apache proxy in a sub- (folder / path / URL).
When starting TiddlyWiki add a path-prefix:
tiddlywiki --listen "path-prefix=/my/path"
The alternative is using a specific tiddler, but that did not work for me for some reason.
AllowEncodedSlashes On # important <Location "/notes"> ProxyPass http://localhost:8080/my/path ProxyPassReverse http://localhost:8080/my/path </Location>
AllowEncodedSlashes was required for me. Did not check the consequences though. Also see here.