Migration to Jazz Team Server - missing administrator rights

Dear Jazz community,

I am using the change and configuration management project dashboard of the Jazz portal (connected with CSnext) for administering a little development project (bug and feature handling).

Today I opened the dashboard again and saw the following:

"Migration Required

Before continuing, existing dashboards must first be migrated to the Jazz Team Server. This is a one-time operation and must be done by an administrator.

You do not have administrator privileges. Please contact an administrator to visit this dashboard (or any dashboard) URL, in order to start the migration."

>> The migration button is read-only for me due to missing administrator rights....

Can anybody help me, who I can contact here??

Thanks in advance!!

Regards,
Christian