With a sync group, you can sync versions across a group of Jira projects.
Go to Version Sync in Project A:
Company-managed: Project A > Project settings > Version Sync
Team-managed: Project A > Project Settings > Apps > Version Sync
Make sure that you are in the tab “Sync versions in a group of projects”
Create new group (e.g. “PA”) with default settings
Go to Version Sync in Project B
Select the group “PA”
Select the desired outcome for synchronization
If applicable sync existing versions from Project B manually
Future version will be synced automatically.