Do not specify a folder for service accounts: instead, use the folder where the account was created.
To use the service, you must have one of the following roles:
resource-manager.cloud.owner(only assigned for the cloud)
Users with a Yandex or federated account need the
resource-manager.cloud.member role for the cloud along with the
admin role. This role is assigned to the user automatically when they are added to the cloud.