How to create record type in App's private database?

Check out this:

https://developer.apple.com/library/archive/documentation/DataManagement/Conceptual/CloudKitQuickStart/CreatingaSchemabySavingRecords/CreatingaSchemabySavingRecords.html#//apple_ref/doc/uid/TP40014987-CH3-SW3

when I ran the app in testflight, it gave out the below error:

CloudKit Operation Error!

ModifyRecords operation hit this error: "Partial Failure" "Failed to modify some records"

"Invalid Arguments"

"Cannot create new type XXX in production schema".

Is the production schema really created automatically? why above error?

So does this mean that you have figured out how to write a record type in Apple's private database in the development environment? If not, start there.

Once you have developed the structure of the records in the development environment, you do something called 'deploy to production'. That takes the records types and indexes and creates them in the production environment. You can create individual records in production but you can't create new record types in the production environment - only in development followed by a new 'deploy to production'..

https://developer.apple.com/library/archive/documentation/DataManagement/Conceptual/CloudKitQuickStart/DeployingYourCloudKitApp/DeployingYourCloudKitApp.html#//apple_ref/doc/uid/TP40014987-CH10-SW2

It needs to go to iClouds dashboard click [Deploy to Production].