Delegating request approval but not attestation responsibility for manager

Hi.

We have OIM 9.1.1 and are using the new Angular UI.

We have a requirement to delegate request approval responsibility for managers. For some managers, an administrative employee will perform these tasks on permanent basis. At the same time, we have a requirement that attestations must be performed by manager, so this responsibility should not be delegated. How can we achieve this in OIM? We thought about using "deputizing delegation" (https://support.oneidentity.com/technical-documents/identity-manager/9.1.1/it-shop-administration-guide/17#TOPIC-1992236). However, we weren't able to show the product in the request portal, even though the service item for "Deputy (temporary)" is active and the user has access to Identity & Access Lifecycle IT shop.

All suggestions are appreciated.

Br,
Tin