You have to apply for another permit or for a permanent residence title in Germany at the local Foreigners’ Registration Office. You can change from the Opportunity Card to a follow-up residence title if you meet the criteria for the other residence titles. This could be language skills or specialist knowledge in your profession. If you have found a part-time or full-time job in Germany via the Opportunity Card, this counts as a criterion for extending your stay in Germany. Changing to a residence title for regular employment is uncomplicated.