Hi Lukas,
Thanks for posting the question on our forum.
According to your description, my understanding is that you access to Office 365 admin center, however, you can’t find the SharePoint admin center option.
If so, I guess that you are not SharePoint admin, you aren’t assign a SharePoint admin roles as below:
I suggest you contact the global admin of your organization to assign it.
If this is not your situation, you are welcome to post back and I will keep working on this.
Regards,
Qing