How to get Shipment comments by comment id Magento 2?

You can check the shipment comments by Magento 2 using Shipment Comment Repository Interface with shipment id.

Shipment comment repository interface used to fetch comment data of a shipment. Useful Interface is, Magento\Sales\Api\ShipmentCommentRepositoryInterface

Check the code to fetch comment by comment id,

<?php
namespace Jesadiya\ShipmentComment\Model;

use Magento\Sales\Api\ShipmentCommentRepositoryInterface;

class ShipmentCommentByCommentId
{
    /**
     * @var ShipmentCommentRepositoryInterface
     */
    public $shipmentCommentRepository;

    public function __construct(
        ShipmentCommentRepositoryInterface $shipmentCommentRepository
    ) {
        $this->shipmentCommentRepository = $shipmentCommentRepository;
    }

    /**
     * Get Shipment comment data
     *
     * @return string
     */
    public function getShipmentComment($commentId)
    {
        $comment = $this->shipmentCommentRepository->get($commentId);
        return $comment;
    }
}

call method from a template or PHP class,

$commentId = 1;
$this->getShipmentComment($commentId);

Pass Comment id, you need to get a comment for the shipment.

You got the response as shipment comment data.