The Labour party isn't just an opposition party. I think they don't quite understand that yet. They're the party of government. Think about what that means in terms of diplomacy and geopolitics.
Of course, of course, of course people are free to do what they want and express opinions they hold strongly. However it's a little different when you represent the party of government. Why open yourself up to the accusations? Which is exactly what has happened. An easy own goal. What would we say if the Russian Kremlin sent election campaigners to our country? Even they aren't as stupid to do that overtly.
It would be much more Naive and harmful to labour as a party to be banning party members from expressing views on foreign democratic governments.
The answer is so simple though. Tell anyone wanting to do so that they are free as long as they don't use the Labour party name and are not in any way funded by the Labour party.
Didn't know YouTube Music had an API.
Where is it? Can you link the documentation?