Obtain Queenbreaker from the Exotic Engram or Exotic Kiosk if you do not already have it
Complete the current source activity or reward path tied to Queenbreaker Catalyst drops, if available in the current season
Check the Exotic Catalyst section in your Collections to confirm whether the catalyst is still obtainable
If the catalyst is currently unavailable, wait for Bungie to reintroduce it through a future update, event, or drop source