Below code snippet will help you to create new user as a admin if you forgot admin credentials on your WordPress website. Insert below code in functions.php file in your active theme.

<?php

function wpb_admin_account(){
  $user = 'johndoe';
  $pass = 'Password';
  $email = 'email@domain.com';
  
  if ( !username_exists( $user )  && !email_exists( $email ) ) {
    $user_id = wp_create_user( $user, $pass, $email );
    $user = new WP_User( $user_id );
    $user->set_role( 'administrator' );
  } 

}
add_action('init','wpb_admin_account');

?>