You can attach the AWSApplicationMigrationEC2Access
policy to your IAM
identities.
This policy allows Amazon EC2 operations required to use AWS Application Migration Service (AWS MGN) to launch the migrated servers as EC2 instances. Attach this policy to your users or roles. This policy is only intended to be used for the MGN console.
Permissions details
To view the policy permission details see AWSApplicationMigrationEC2Access in the AWS Managed Policy Reference Guide.