After investigating, I discovered the issue was caused by a typo in the endpoint URL. I had written Commnets instead of Comments. Correcting the typo resolved the issue.

Here’s the corrected configuration that worked for me:

HTTP Request Configuration

Method: POST

Endpoint:

_api/web/lists/getbytitle('Project Tracker')/items('ItemID')/Comments

Headers:

{
    "accept": "application/json;odata=verbose"
   
}

Body:

{
    "text": "This is a new item."
}

I hope this helps anyone facing a similar issue! If you have any further questions or suggestions, feel free to share them in the comments below. 😊