How to add a single index to the createdAt field Mongo

I have a collection in which I need to make queries filtering by date, so I’d like to add an index to the createdAt field.

I already added indexes for other fields in /models/{name}.settings.json

but there is not createdAt attribute in the /models/{name}.settings.json file

System Information
  • Strapi Version: 3.6.8
  • Operating System: Windows
  • Database: MongoDB
  • Node Version:
  • NPM Version:
  • Yarn Version: