No, the German word has no umlaut but the pronounciation is as if it had. And "Ä" is not a diphtone like she is saying. It is like the "ai" in "said". Or the "a" in "fan". I find it difficult to write a pronounciation in English for vowels when they are spoken so differently for different words. It is not the "ai" in "lain" or "brain". So I used the German vowel "ä" which has only one way of pronouncing it. I am sorry for the confusion. She sounds like saying "Fehns" or even "Feyns" (again the German way of pronouncing this). Which is wrong.
In German that would be one acceptable pronunciation. Most of the words with French heritage that are written the same as in French should be pronounced French. Of course most Germans speak them with a German accent. That means for example the "nt" in "Restaurant" is often not spoken through the nose. But to speak it French is not wrong.
Well, my point was that an English loan word ( at least I think "fan" is borrowed from English; I learn something new every day ) should be pronounced without a German accent, if it is going to be used in a language learning course; otherwise one can become confused. Of course Americans are equally guilty of pronouncing words such as "ueber" as "OO-ber" in everyday language. And so it goes.
Adjective endings! If "acht" meant "respectful" in this case, it would have to take the "-e" ending, so the sentence would be "Sie möchten achte Fans" rather than "Sie möchten acht Fans". Since it's "acht" rather than "achte," you know it's not an adjective here.
No argument that "respectful fans" is a much less weird sentence in English than "eight fans," though.
I'm a little puzzled by the fact the DUO accepts both the present and the conjunctive tense in English. You can answer both: 1) They like eight supporters 2) They would like eight supporters.
But the meaning seems to be very different. in 1) it seems you are talking about already existing supporters (e.g. I have a lot of fans but I like eight of them), while in 2) you talk about something not necessarily existing (I would like eight supporters, because they can attach flyers of my next show).
Here's a good explanation of the Subjunctive:
indicative "mood" is the everyday form of a verb so in this example it means "I like 8 supporters", the conditional uses the subjunctive mood and means "I would like 8 supporters".
There are two possible meanings of the conditional statement valid in both languages. One is "I would like (all) 8 supporters (as friends), if I supported their team" the other is "can I please have 8 supporters" (maybe a film director directing extras would say this).