Hello and welcome to Apple Support Communities ürnieball,
Congratulations and thank you and for contacting us regarding your new iPhone 12 Mini. You have come to the right place and we are happy to assist you. If we understand correctly, you are wanting to use the iPhone with a dual SIM or eSIM. We can understand why you’d reach out for a solution. We would direct you to contact your carrier first, to see what options they provide. Second we recommend you contact the location where you purchased the iPhone. Both places will be able to provide you with the answers to your question.
Thank you for contacting Apple Support Communities.
Best regards.