Mongodb Collation issue. I have a usecase that i need a field like name should be unique such that it should consider "John Jacob", "john jacob", "John Jacob" as same. but it should not consider "John Jacob Jafrrie" as same value

I’m using this collation option
locale: ‘en’,
caseLevel: false,
strength: 2,
alternate: ‘shifted’,

to create index with unique and collation

What to do with regex? I want to create index.

Sorry, it gives error in collation as it considers same john-jacob-jafrrie and “john jacob”