With the current releases you need to pass an EntityType enum for resource_type argument and a PermissionSubjectType enum for subject_type.
res = gmp.create_permission(
name=‘delete_target’,
subject_id=GROUP_UUID,
subject_type=gmp.types.PermissionSubjectType.GROUP,
resource_id=TARGET_UUID,
resource_type=gmp.types.EntityType.TARGET
)