To integrate Cloudflare Healthchecks with PagerDuty, you will first need to set up a PagerDuty account, and follow the steps outlined in this guide to create email integration within PagerDuty.
PagerDuty will generate an email address that will create incidents based on emails sent to that address.
If you already have email integration configured in PagerDuty, you can find the designated email address by going to Configuration > Services > Email (under Integrations)
When creating the Notifier object, configure the Email to go to the PagerDuty integration email.
Consequently, whenever a pool, or an origin goes down, an Incident will be created to capture it.