Can I edit a field in the schema and its properties?
If your collection contains records and is not empty, you can:
change 'description' of a schema field
change 'mode' to a less restrictive value ('UNIQUE' -> 'REQUIRED' -> 'NULLABLE')
change a field to be ‘indexed’
All other properties of a schema field cannot be changed if your collection already contains records. There are possible workarounds:
Add a new field with a different name with the desired properties
Remove all the records from the collection, make the changes to the schema, and then add the records again.
Alternatively, you can also start again by creating a new collection.