XML file into body with variable

Through the binary option I select an XML file which is posted to the api I’m using (only XML format allowed).
However, In the XML file there are some variables that need to be filled in from the values I declared beforehand.

When I copy the XML file into the body, it works fine and fills in the variables. However I’m doing this manually.
So 2 questions:

  1. Can I copy/parse the contents of the file into the body of my request, as is, without any changes to the format automatically, so it can fill in the variables
  2. Can postman fill in the variables in the xml and then post them