Hello pavento,
We detected that you posted in German. Since this is an English forum, I will reply you in English. Your understanding is much appreciated.
Do you mean you cannot find Outlook Customer Manager in Outlook? If so, please kindly contact your admin to assign you a Business Premium license. Then Customer Manager add-in will install automatically in Outlook after 24 hours.
For more information about it, you can refer to: Get started with Outlook Customer Manager.
Thanks,
Sylvie