Hi Vamsi,
Thank you for posting your question. To quickly clarify the ask is to use Basic Auth to validate an incoming request to a API ( triggered task) ? If you are using Ultra we disable the use of Basic Auth in the SnapLogic Plaform, You can authenticate to an API (triggered task) using Basic Auth by providing the username and password as a base64 encoded string in the Authentication header. Format is <username>:<password>
And to add there is no policy required to be created/enabled to authenticate using Basic Auth for triggered tasks.
Here's an eg curl command
curl --location <triggered-task-url> \
--header 'Authorization: Basic <base64 encoded username:password> ' \
Hope this helps! Please reach out if you have any questions.