Add custom user roles to enforce 2FA by email using Shield Security plugin for WordPress

functions.php

<?php

/**
 * Adding custom roles is a case of using the filter provided, adding your
 * roles to the array of roles that has 2FA by email forced upon them.
 *
 * The role you add will be the 'slug' of the role, not the name of the role.
 * For example, WordPress comes with built-in roles such as Administrator.
 * The slug for this role is 'administrator', not 'Administrator'.
 */
add_filter( 'odp-shield-2fa_email_user_roles', function ( $roles ) {

	/**
	 * The role you add is the 'slug' for the role, not its pretty name.
	 */
	$roles[] = 'my-custom-role';

	// To add multiple roles you can either:
	// 1. add each role individually
	$roles[] = 'my-custom-role-1';
	$roles[] = 'my-custom-role-2';
	$roles[] = 'my-custom-role-3';

	// 2. Or merge 2 arrays (this is probably the neater method)
	$roles = array_merge(
		$roles,
		[
			'my-custom-role-1',
			'my-custom-role-2',
			'my-custom-role-3',
		]
	);

	// ALWAYS return $roles.
	return $roles;
} );