Shell error occurs when formatting code includeing backquote(`)

example:

let _ = "`"

When I format code including single quotation, for example type variables, error always occurs.

cause:

e.g.

let sum: 'a -> 'b -> 'c = fun x y -> x + y;;

↓ sanitize

let sum: '\''a -> '\''b -> '\''c = fun x y -> x + y;;

Just installed this extension and the latest ocamlformat via opam (windows 10).
I am getting this error:

``
Error: Command failed: dirname d:\CRIME\ocommander\src\ocommander.ml 'dirname' is not recognized as an internal or external command, operable program or batch file.

the file d:\CRIME\ocommander\src\ocommander.ml exists and that is what I am trying to format. No idea what dirname is and how to set it.

Does "ocaml-formatter.profile" have to do with anything?