How do we remove “Pay by wallet” option if the user uses any coupon code.

I am trying to limit the user to either use the coupon code or the “Pay by Wallet” one at a time but not in conjunction.

Somehow it’s not working.

// Disable Coupon when cashback is used.
add_filter('woocommerce_available_payment_gateways', 'applied_coupons_hide_payment_gateways', 20, 1 );
function applied_coupons_hide_payment_gateways( $available_gateways){
    // Not in backend (admin)
    if( is_admin() ) 
        return $available_gateways;

    // If at least a coupon is applied
    if( sizeof( WC()->cart->get_applied_coupons() ) > 0 ){
        // Loop through payment gateways
        foreach ( $available_gateways as $gateway_id => $gateway ) {
            // Remove all payment gateways except BACS (Bank Wire)
            if( $gateway_id != 'wallet' )
                unset($available_gateways[$gateway_id]);
        }
    }

    return $available_gateways;
}

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