Need a Data Layer JavaScript custom code for GTM (Google Tag Manager)

******* Visual explanation of project: [login to view URL] ******** -------------------------------------------------------------------------------------------------------- (ATTENTION: I already have a done script - The Google Ads global site tag, there is already shown what I want to push into the data layer, you just need to take those options and implement them in a new code file). I need a custom made javascript code to copy it either in my theme's template code or in the GTM, so it could push the dataLayer google_tag_params variables (ecomm_pagetype, ecomm_totalvalue, ecomm_prodid and ecomm_category) into the data layer of any page of my website. As well I want to push custom events to the dataLayer depending on what page the visitor is looking on or what is he doing on the website (product page viewed event, add to cart event, purschase event). I have a reference script here. It is of the Google Ads's Global Site Tag ([login to view URL]). However, I want a code exactly like this but one that didn't sent anything to Google. Just pushed the three keys and their values to the dataLayer like here ([login to view URL]). -------------------------------------------------------------------------------------------------------- Therefore I am paying for: 1) The custom code that will sent the parameters of the products and the actions of the users in form of events into the data layer so I could see them in 3 places. The Debug mode in GTM ([login to view URL]). In dataLayer of the js page ([login to view URL]) and in Google Tag Assistant like here ([login to view URL]) 2) Help me to understand why GTM can define a data layer variable if I create it in GTM Variables with the right javascript path. ([login to view URL]) -------------------------------------------------------------------------------------------------------- Purpose: Visual explanation: [login to view URL] WIth the help of the variables' values and events pushed into the data layer by the custom code, I want to capture them into Google Ads and Google Analytics tags in GTM and therefore send the events and data to Google Ads and Google Analytics dashboards. Therefore you need to be pretty familiar with GTM and javascript coding as well.