Without enabling hook script support, you can not use any of the add-on features.
https://developer.atlassian.com/server/bitbucket/how-tos/register-maintain-hook-scripts/
Starting from Bitbucket Data Center 8.18, hook script support is disabled by default. However, you can enable the feature at any time.
If hook script support is an integral part of your workflow, we strongly recommend setting the relevant property to enable the feature prior to the upgrade.
To do this, in the bitbucket.properties file, set the property feature.hook.scripts=true. Then, restart Bitbucket for the changes to take effect. If you run a Bitbucket cluster, a rolling restart is enough to pick up the configuration properties you set to enable the features.
