My_Test_Repo/force-app/main/default/classes/SaveToPDF.cls

public with sharing class SaveToPDF {

    // Determines whether page is rendered as a PDF or just displayed as HTML
    public String renderAs { get; set; }


    // Action method to "print" to PDF
    public PageReference print() {
        renderAs = 'PDF';
        return null;
    }

}