Hi, @Jonas Welcome to the Microsoft Q&A forum, Thanks for posting your question and for using Azure services.
As we understand the ask here is you are trying to enable timescaledDB for PostgreSQL Flexible (PostgreSQL 14) and you are receiving the error
I think that you have added shared_preload_libraries,however, you also need to add the timescaledb under server parameters search for azure.extensions as shown below
Once this is added connect to your database and run the query
Please let me know if you need any additional information.
Regards
Geetha