Is there any way to migrate users to gitlab.com

I’m tying to make a migration script from our current GIT to GitLab.com server and I get stuck with importing users into the group with specific access permissions (Reporter/Developer/Maintainer).

My initial plan was to find the API method to invite ~200 users into new GitLab Group or Project according to the current permissions. But unfortunately, it looks like that this is possible only through UI and even straight user creation require Admin token, which I think is impossible to obtain in case of gitlab.com.

May be there is still some way to achieve that?
Thank you!