Modify POS Page

Hello, I am currently working on modifying the POS page in offline mode, I want to add a field,a button, as well as some styling it will look something like this

but I can’t seem to render new my custom template using the frappe.render_template command to replace the existing template so it can be accessed by ERPNext in the js script, I placed the HTML in the same directory as my js script but i have still not been able to solve this.
I have added my html to build.json and added it to app_include_js variable in hooks of my app as stated here
Pos HTML Template here
Js script for POS in offline mode here

Any Assistance or clue towards solving this would be appreciated.

Hi. Can you send a screenshot of what you’re trying to achieve and send a link to the POS js and template files you’re trying to modify?