mass_contact.install

<?php

/**
 * @file
 * Install hooks for the mass contact module.
 */

use Drupal\mass_contact\MassContactInterface;

/**
 * Implements hook_install().
 */
function mass_contact_install() {
  // Add the `mass_contact_opt_out` field to the user form.
  $display = \Drupal::service('entity_display.repository')->getFormDisplay('user', 'user', 'default');
  if (!$display->getComponent(MassContactInterface::OPT_OUT_FIELD_ID)) {
    $settings = [
      'type' => 'options_buttons',
      'settings' => [],
    ];
    $display->setComponent(MassContactInterface::OPT_OUT_FIELD_ID, $settings);
    $display->save();
  }
}
 
/**
 * Implements hook_unistall().
 */
function mass_contact_uninstall() {
  //Removing mass_contact_opt_out field.
  Drupal::configFactory()->getEditable('field.field.user.user.mass_contact_opt_out')->delete();
  Drupal::configFactory()->getEditable('field.storage.user.mass_contact_opt_out')->delete();
}