And a thorough description of the problem / question:
SonarQube 9 is reporting issues such as:
Refactor this method to reduce its Cognitive Complexity from 27 to the 15 allowed.
How can I increase the ‘allowed’ value? Looking at the referenced code I would like it to be 30 before being flagged.
Connect to your SonarQube server. This will apply in SonarQube for IDE the same rules that are applied server-side
Make sure your project is using a custom quality profile (either as the default or through direct assignment) on the server.
Update the threshold for that rule in your profile to your desired value. This should probably be done in discussion with your team and/or SonarQube admin.