No users with roles in Dynamics Online instance

Hy,

We can't connect on our environement because we have no users with role (administrator as well). It appends when we create and assign new business unit to our users.

So we can't connect with any administrator user and can't assign new role to others.

We are stuck ? How can we do ? We can't find a way to assign administrator role on Office365 portal.

Thank you for you help.