Question about the format of recommendation letter for master admission

Es tut mir leid, ich Englisch verwendet, um das Problem zu beschreiben!

I am from a non-English-Speaking country and I am preparing materials for master program at German universities. My instructor (he is an American Associate Professor or a British Senior Lecturer ) asked me to write an English draft for him. But I still cannot figure out the job title of the sender in German style .Should I write ‚Professor Dr‘ or ‚Senior Lecturer‘ or ‚Associate Professor‘ ? I searched some articles, in which they say that ‚Associate Professor‘ can not be used to address to an Associate Professor in written letter. But here the problem is the title of the sender. There is a brief example (British style), is it appropriate? or I just upload the daft. Thank you!! It is really URGENT!

Professor Dr XXX
XXX University
Address
Tel and Email

XXX University
Department of XXX
Address

                                                                                                       Location and Date

                                                 Title

                                                Text

Sincerely,

(Signature)

Professor Dr XXX

Hi WangJi,

does your professor have an official letterhead? If yes, this should typically show his title, name and position (in the style which is common in his country). „Professor Dr. XY“ would be common in German, but in other countries, these academic titles are not used like that.

I am working as senior researcher at an university. If I get such letters of recommendation from students and I do not know the person who wrote this letter, then I am looking for his name, position, institution and a website or I simply search for references (papers) of this person - this will tell me more than appropriate titles. I would find it rather strange to see the name with academic titles in German style (as above) in a country which usually has a different way to write titles.

Good luck with your application!
Eva