Fix Enhanced Conversions Setup

My Google Ads enhanced-conversion tags fire, but the conversions never process because the user-provided data isn’t being sent. Email addresses are captured only at the point of sale, yet no CSS selector or JavaScript variable was defined during the original setup to pass that data to Google.

Here’s exactly what I need:
• Add the correct selector or data-layer variable to capture the customer’s email (and any other available identifiers) at checkout.
• Update the existing gtag/Google Tag Manager implementation so the hashed data reaches Google Ads in the required format.
• Verify the tag in real time with Tag Assistant and confirm that enhanced conversions appear in the Google Ads diagnostics after 24–48 hours.

Acceptance will be based on Google Ads showing “Recording (processing)” followed by “Recording (processing finished)” for enhanced conversions, with counts matching the standard conversion tag for the same period.