After checking the bug comes in the name given to the methods of the Ogone extension.
This one uses capital letters, that’s why the filter did not work.
In your example uses this :
function woa_custom_gateways_hook( $gateways ) {
$gateways[] = 'paypal';
$gateways[] = 'OgoneCw_CreditCard';
$gateways[] = 'OgoneCw_AmericanExpress';
return $gateways;
}
add_filter( 'woo_cao_gateways', 'woa_custom_gateways_hook', 10, 1 );
Here is the list with capital letters to respect in the filter for the plugin to work:
OgoneCw_Acceptgiro
OgoneCw_AirPlus
OgoneCw_AmazonCheckout
OgoneCw_AmericanExpress
OgoneCw_Aurore
OgoneCw_BankTransfer
OgoneCw_Bcmc
OgoneCw_BelfiusDirectNet
OgoneCw_CarteBleue
OgoneCw_CashTicket
OgoneCw_CashUPrepaid
OgoneCw_CbcOnline
OgoneCw_CenteaOnline
OgoneCw_Cofinoga
OgoneCw_Dankort
OgoneCw_Diners
OgoneCw_DirectDebits
OgoneCw_DirectEBanking
OgoneCw_DiscoverCard
OgoneCw_EDankort
OgoneCw_Eps
OgoneCw_FidorPay
OgoneCw_Giropay
OgoneCw_IDeal
OgoneCw_IngHomePay
OgoneCw_InstalmentInvoice
OgoneCw_InterSolve
OgoneCw_Jcb
OgoneCw_KbcOnline
OgoneCw_LaserCard
OgoneCw_Maestro
OgoneCw_MaestroUK
OgoneCw_MasterCard
OgoneCw_MasterPass
OgoneCw_Mpass
OgoneCw_OpenInvoice
OgoneCw_PayPal
OgoneCw_Paysafecard
OgoneCw_PingPing
OgoneCw_PostFinanceCard
OgoneCw_PostFinanceEFinance
OgoneCw_SoloCard
OgoneCw_Threexcb
OgoneCw_Tunz
OgoneCw_Twint
OgoneCw_Uatp
OgoneCw_UnEuroCom
OgoneCw_Visa
OgoneCw_CreditCard