Bulk Members Import into class groups

Please I have two issues; How could I achieve bulk import of users into class group instead of adding them one after the other? After creating of a custom role with all permissions needed assigned, I assigned it to a user I created. But when I logged in with that same account, I could not see Admin Opigno Block - picto (Administration Menu) icon. Please kindly put me through on how to fix this issues. Thank you in anticipation.