Drupal 9

Example : Change title

Select:

    $con = \Drupal\Core\Database\Database::getConnection();

    $query = $con->select('table_name', 't')

        ->fields('t', ['field_1', 'field_2']);



Step 1:  Create a module. (Example)

Example 1. Redirect to the front page:

    return new \Symfony\Component\HttpFoundation\RedirectResponse(\Drupal::url('<front>'));

Example 2. Redirect to a route path (user page):

Get the image file src (url)   

    $fid = 1;//The file ID   

    $file = \Drupal\file\Entity\File::load($fid);

    $path = $file->getFileUri();



Change on a form or controller

Just set ['#title'] element.

Form Example : $form['#title'] = "The title";

Example with a module 'mymodule'

Step 1.

Create if not exist yet, mymodule.permissions.yml (root of mymodule)

Add your new permission like:

There are several ways to do that.