Increase shipping cost by selecting cod

Hello,

I want to increase shipping cost if any user select the COD payment method.

I tried below code:

add_filter( 'woocommerce_package_rates', 'custom_shipping_costs', 10, 2 );
function custom_shipping_costs( $rates, $package ) {
    
    $tax_rate = 25;
    
    $payment_method  = 'cod';

    $chosen_payment_method = WC()->session->get('chosen_payment_method');

    if( 'cod' === WC()->session->get('chosen_payment_method') ){
        foreach( $rates as $rate_key => $rate ){
			
				// Set rate cost
				$rates[$rate_key]->cost = $rates[$rate_key]->cost + $tax_rate;

		}
    }

    return $rates;
}

If I remove the payment gateway IF condition then its working. but with the payment gateway condition its not working. Can nayone help me out with this?