Hi,
I also don't see why they would make a different page instead of just changing the page they already have to include the responsive.
But well, let's work with what we have.
In the file plugins/hikashoppayment/paybox/paybox.php, you'll find the code:
$this->url = 'https://'.$srv.'/cgi/MYchoix_pagepaiement.cgi';
if(!empty($this->payment_params->iframe)) {
$this->url = 'https://'.$srv.'/cgi/MYframepagepaiement_ip.cgi';
}
You can try changing it to:
$this->url = 'https://'.$srv.'/cgi/FramepagepaiementRWD.cgi';
if(!empty($this->payment_params->iframe)) {
$this->url = 'https://'.$srv.'/cgi/MYframepagepaiement_ip.cgi';
}
Then, check that you have the "iframe" option turned off in your paybox payment method.
Please let us know how it goes.
We could potentially add that change on our end if that works fine and provide a better experience so that no modification would be required for anyone else nor for future updates of HikaShop on your end.