Bulk adding can be either done via REST or Workflow API. For the former, there's a ready-to-use example. For the latter, you can get values of the field using the BundleProjectCustomField object and add new values via a createValue() method. If you are not familiar with the workflow functionality, please refer to our tutorial.
Hi!
I'm Sergey from the YouTrack team.
Bulk adding can be either done via REST or Workflow API. For the former, there's a ready-to-use example. For the latter, you can get values of the field using the BundleProjectCustomField object and add new values via a createValue() method. If you are not familiar with the workflow functionality, please refer to our tutorial.