edit this text please : Dear Anna, 
I hope this email find you well. Last year, I with my wife and daughter visited you at Hagen Immigration Office to extend our visa, that led to extension of our visa for 8 months until the end of August 2023. here I need to appreciate you. 
As I mentioned earlier, I am a visiting researcher at university of Hagen, that my visa will be valid until the end of August 2023.  Now the university is extending my stay for one year more until the end of August 2024, and now I want to apply for extension of my visa and the visa of my wife and my daughter. my question here: 

Considering that I am currently in Tehran and it is possible that I will be in Tehran in two months, can I go to the German Embassy in Tehran for the extension of our visa?
And besides the hosting agreement that the university is going to issue next week, are there any other documents needed?
 I would appreciate it for your quick reply. Thank you so much for your help. 
Best regards, 
Ahmad 
