Express-handlebars. How to compile a template file?

Question

JavaScript

Hello!
We set a goal to send a letter, but from a template file using express-handlebars.
Template file example:
Hello {{ fullName }}!
As I understand it, I need to compile this template at the beginning, and then send this data (I use nodemailer).
So the question is - how to compile a template file using express-handlebars?
I saw examples on the net that this file is read using the fs object in nodejs. But I don't know if this is correct or not.
Thank you in advance.