With the HTTP request action, you can use the "retry on status" or the "retries" options available for the action. Select the HTTP request action to set these and click "+ Option". This lets you choose how many times to perform a retry on the HTTP request action if it fails the first time. Leverage the "retry on status" to determine what status codes it should attempt a retry - like 429. 429 is the status code for a service being busy.
By default, Tines will silently attempt a retry, but by leveraging the "retries" field, you are able to give yourself more room for control.
To learn more about the event transform action, see here.