SarahT, you are correct. When writing "any more" as two words, it refers to quantity. For example, "Do you want any more fish?"
When writing "anymore" as one word, it is an adverb that refers to time. For example, "Why don't you bake fish anymore?"
When doing this exercise, I wrote "The fish isn't fresh anymore." Although this is correct English and Duo accepted it, Duo told me that I was missing a space between the words "any" and "more" by showing "any_more" No, Duo, I should not have a space between the words "any" and "more" in this exercise because it is referring to time. Bad owl!
Fred the fisherman's apprentice is fishing for fresh fish; fresh fish is what Fred the fisherman's apprentice is fishing for.
Or possibly: Fred Fisher is fishing for fresh fish; fresh fish is what Fred Fisher is fishing for.
(Depending on whether Fischer is a noun referring to a fisherman or a family name.)
Fritz is a nickname for someone called Friedrich, so I've translated it as "Fred", a common nickname for someone called "Frederic".
From Merriam Webster dictionary:
Definition of no more (adverb)
1a : no longer: those stately homes stand no more
b : no longer in existence: dead, departed the glory of his house is no more; the great leader is no more
2 : to no greater extent, in no greater degree: can no more attempt to do intricate law-business than to play the piano — W. M. Thackeray
3 : nevermore: these fields and hills shall see thee no more
4 : neither: he won't hear of it. No more will I — W. C. Williams; no more you'll have to, if you don't want — William Faulkner
(Apologies for all the double line feeds; I don't know how to get DL to make a paragraph structure otherwise)