How can we add the new blueprint fragements?

You can take a copy of your BetterLoot........."Data/LootTables.json". Out of your Data Files. Go to; editor.looty.cc/betterloot-v4. Put that Copy in here. It gives all the Items found on the Server. Take your your NEW copy....after you have added the Blueprints and any other New Items.
In your server Console or RustAdmin Panel. Type..../o.unload BetterLoot. Remove your cs. file for Betterloot that you made a copy of. Upload the new one you made. And type....... o.reload BetterLoot. Once  you have reloaded the updated Data json. You should now have all the new items you added in your crates or barrels. If not? Maybe just restart your server. Re-doing my lootables in Looty. Puting it back in. Reloading the plugin worked fine.
  Hope this helps......

TheEye

You can take a copy of your BetterLoot........."Data/LootTables.json". Out of your Data Files. Go to; editor.looty.cc/betterloot-v4. Put that Copy in here. It gives all the Items found on the Server. Take your your NEW copy....after you have added the Blueprints and any other New Items.
In your server Console or RustAdmin Panel. Type..../o.unload BetterLoot. Remove your cs. file for Betterloot that you made a copy of. Upload the new one you made. And type....... o.reload BetterLoot. Once  you have reloaded the updated Data json. You should now have all the new items you added in your crates or barrels. If not? Maybe just restart your server. Re-doing my lootables in Looty. Puting it back in. Reloading the plugin worked fine.
  Hope this helps......

English Translation:

I tried this method.
In my environment, I have a profile set up that adjusts locked crates so that weapons don’t drop very often, and when I tested it, the weapon drop rate followed the settings correctly.
However, regarding blueprint fragments, sometimes they appear and sometimes they don’t, so I think this season’s update, “Locked crates will always drop 2 blueprint fragments,” is not being applied.