If you want to add an animated countdown timer into your HighLevel email you can follow the instructions here: How to Add Email Countdown Code to HighLevel

In your campaign, navigate to the 'Emails' tab in the left hand menu.

In the top section of this page you'll see your Integration settings listed, including your Custom Field:

Important Note: There can be a delay between when the webhook triggers the deadline for a contact and when the contact's custom field gets populated with their deadline. Because of this, we recommend that you don't use the custom field in your emails until at least one day after the deadline is initially triggered.

In your email editor, place the cursor where you want to add the dynamic date and time and click 'Custom Values':

In the drop-down, scroll to Contact >> Custom Fields and select your custom field:

This will insert your custom field placeholder into your email:

If you are being tracked for this campaign and send yourself an email you will see that the placeholder has been replaced with the deadline text format you chose in your setup.