Does this mean that you can not set a value for the api-key and the TYPSENSE_API_KEY that is different from the key that is automatically generated and inserted into the typesense-server.ini file when you

Only the DEB and RPM installers auto-generate the API Key in typesense-server.ini when you install them. But at installation time, if you already have a typesense-ini file, you should see an option from the package installer asking if you want to use your existing config file or if you want to overwrite with the auto-generated one.