Following resource types are not supported for resource import

Using downloaded JSON template (Authentication Template)

Error is thrown when uploading to AWS CloudFormation: The following resource types are not supported for resource import: Custom::InvokeLambda

Even after removing the Lambda resources in the Inventory config. Still get the same error.

Not sure if this helps:
Resources to import must have a DeletionPolicy attribute specified in the template.
Verify that resources and their properties defined in the template match the intended configuration of the resource import to avoid unexpected changes.

Start by reproducing the failure with the downloaded Authentication Template in AWS CloudFormation, then compare the template's resources with the Inventory configuration after Lambda resources are removed. Check why Custom::InvokeLambda remains in the import request and whether the template's DeletionPolicy requirements are met. The issue names no repository files or tests, so done means identifying and correcting the generated import template or documenting the required configuration.

Written by the indexing model from the issue text.