Anki's menu bar ➡️ tools ➡️ add-ons choose "Beautify Anki" then > Configuration
note_correction_factors
as follows to add a line that includes the beginning of the deck name (including all superdecks) and the number of different cards in the note type in the deck.
example :
"note_correction_factors": { "Custom": 2 , "English" : 3 }