Meta Spatial Anchors saving anchors

I am working on implementing Spatial Anchors in my app. I used this tutorial: Meta Quest Spatial Anchors Tutorial 
In the tutorial he only shows how to spawn, save and load one prefab, but my app needs different prefabs. 
I have figured out how to spawn in different prefabs with a Spatial Anchor component, but the saving is the thing I can't figure out. 

I have tried to find other tutorials, but they all only save one prefab. 

Any ideas on how to do that or where to find more information on this?

Thank you in advance.

I can't put the scripts in because they are too long for this post.

The scripts are on the Unity Discussion forum:

Meta Spatial Anchors saving anchors