Woocommerce add a number of fee strategies [closed]

I’m making an attempt so as to add a number of fee strategies in WooCommerce by one class. Right here is my operate

operate add_gateway_method( $strategies ) 
{
    
   array('bank card','paypal','echeck');
    $strategies[] = 'PaymentGateway';
    
    return $strategies;
}

Can anybody assist me how do I do that?

php