How to call Power Automate from Custom Action

1. Create Yes/No Field called  "Send Attachment" with a default  "No"
2. Create the Activity "Update Send Attachment Field" where we set the field value for Send Attachment to "Yes"
   
   
3. Create Custom Action "Send Attachment" which will call activity "Update Send Attachment Field"
   
   

4.   Create Power Automate, triggered when the item created or updated with the condition Send         Attachment is equal to true. After the email send it should update the Send Attachment field           to No.