I have issues with my sim/esim

I WANT to reactivate my sim card to receive messages. I mistakenly deleted the esim I had from my original mobile phone (iphone) and my sim card is not working and I can't receive sms so I can reactivate my esim, We need the Qrcode to be able to reactivate my esim card to work on my mobile. I am outside Germany and will be in Greece for a few more weeks and we need the phone number.
Please help us with this, it is absolutely necessary

Edit o2_Bianca: Moved from SIM Karte Betsellung&Aktivierung to English o2 Community mobile