Enable other content type to be visible on New Button for libraries with multiple content types

Hi,

Good day! We are migrating content from SharePoint 2010 on premise to SPO. We have libraries that configured to allow multiple content types but only the default content type is visible in the New Button for adding an item after our migration. We have a custom scripts that we execute after our migration to enable the other content type but we advice to incorporate it using transformations. We would like to know if it is possible to enable other content types in libraries with multiple content types using transformations to be visible in the New Button for adding an item?

Thanks,

Allan