Create Comments in Drupal 8 Programmatically

// To create a new comment entity, we'll need <code>use</code> (import) the Comment class.
use Drupal\comment\Entity\Comment;
 
// The function name doesn't matter. Just put the the function body where you need it.
function my_modules_function_or_method() {
 
  // First, we need to create an array of field values for the comment.
  $values = [
 
    // These values are for the entity that you're creating the comment for, not the comment itself.
    'entity_type' => 'node',            // required.
    'entity_id'   => 42,                // required.
    'field_name'  => 'comment',         // required.
 
    // The user id of the comment's 'author'. Use 0 for the anonymous user.
    'uid' => 0,                         // required.
 
    // These values are for the comment itself.
    'comment_type' => 'comment',        // required.
    'subject' => 'My Awesome Comment',  // required.
    'comment_body' => $body,            // optional.
 
    // Whether the comment is 'approved' or not.
    'status' => 1,                      // optional. Defaults to 0.
  ];
 
  // This will create an actual comment entity out of our field values.
  $comment = Comment::create($values);
 
  // Last, we actually need to save the comment to the database.
  $comment->save();
}