“Typer” is a not a word — at least not one that I have ever heard. More specifically, “typer” can mean “a person who types (such as on a typewriter)”, but that makes no sense here. There is no meaning of “typer” that makes sense in your sentence.

Google gives zero hits on the sentence. It's often a good sign that something is wrong. :)

Hmm, I guess the sentence is incorrect. It's not mine, I just read it in the text, may be there is a misspelling there. Thank you guys.

Your sentence does not make sense. A type is a category or type of person, typer is on rare occasions used to mean a typist.