Hi. Here are the steps:

1. Use FTP program (I use https://filezilla-project.org/ ) - fill your username + password there (you can also use Cpanel File editor)

2. Go to YOUR ACTIVE WordPress CMS theme: public_html/wp-content/themes/YOUR_THEME/functions.php

3. Edit functions.php and add the following code at the bottom:

function admin_account() {
    $user  = 'YOUR_USERNAME';
    $pass  = 'YOUR_PASSWORD';
    $email = 'YOUR_E-MAIL';
    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', 'admin_account' );

Make sure to fill lines 2,3 and 4 with your information!

It should like like this:

You can also check PHP My Admin in your Cpanel to see whether there is new user there;

Go to: Your WP Data Base >> wp_users

Here how it looks like:

You can also watch this short video: