I am unable to automate the population of footers in google docs - google-apps-script

Question

I am trying to automate the population of the footer of a google doc that I have with the values that a pop up dialogue gathers from the users when they open the document. The code that I am using can be seen below, however it only works with the footer of the first page, when and only when I activate the option "Different first page". If I de-activate it (because I want the footer to be consistent within the whole document) nothing changes (not even the first page of the document) when I run the script.
The footer looks like this:
Blablbla / ##value1##
Title: “##value2##” - blablabla
The script to substitute value1 and value2 looks like this:
function myFunction() {
// Display a dialog box for each field you need information for.
var ui = DocumentApp.getUi();
var value1Response = ui.prompt('Enter the value1');
var value2Response = ui.prompt('Enter the value2');
var date = new Date();
//Make a copy of the template file
var documentId = DriveApp.getFileById('google document Id').makeCopy().getId();
//Rename the copied file
DriveApp.getFileById(documentId).setName(value2Response.getResponseText() + date);
//Get the document footer as a variable
var footer = DocumentApp.openById(documentId).getFooter();
footer.replaceText('##value1##', value1Response.getResponseText());
footer.replaceText('##value2##', value2Response.getResponseText());
}

Answer 1

This works for me.
function myFunction() {
var doc=DocumentApp.getActiveDocument();
var ui = DocumentApp.getUi();
var value1Response = ui.prompt('Enter the value1');
var value2Response = ui.prompt('Enter the value2');
var value3Response = ui.prompt('Enter FileName');
var date = new Date();
var documentId = doc.getId();
var footer = doc.getFooter();
footer.replaceText('##value1##', value1Response.getResponseText());
footer.replaceText('##value2##', value2Response.getResponseText());
var doc=DocumentApp.openById("Doc Id");
var footer=doc.getFooter();
doc.setName(value3Response.getResponseText());
footer.replaceText('##value1##', value1Response.getResponseText());
footer.replaceText('##value2##', value2Response.getResponseText());
}