@Rajesh Ambakkat Thanks for reaching out. As you want to purge the cache in front door using logic app then you can leverage the Purge Content REST API and call this API in HTTP native connector within logic app. You can call any HTTP or HTTPS endpoint from logic app leveraging the HTTP native connector.
To get familiar with Azure REST API you can refere to this document.
Feel free to get back to me if you need any assistance.