Hi sorry for delayed response.
You can do that using template override. If don't know how to create override, you can follow this video :
https://www.youtube.com/watch?v=tMB97xfYQfYAfter you have created override for whatsapp module, then change these code of default.php (line 290) :
if($watarget == 0){
$clickdirect = 'onClick="parent.location=\'https://'.$waurl.'.whatsapp.com/send?phone='.$item->agent_phone_number.'\'"';
}else{
$clickdirect = 'onClick="parent.open(\'https://'.$waurl.'.whatsapp.com/send?phone='.$item->agent_phone_number.'\')"';
}
into
if($watarget == 0){
$clickdirect = 'onClick="parent.location=\'https://wa.me/send?phone='.$item->agent_phone_number.'\'"';
}else{
$clickdirect = 'onClick="parent.open(\'https://wa.me/send?phone='.$item->agent_phone_number.'\')"';
}
and this one (line 579)
if ((/Firefox[\/\s](\d+\.\d+)/.test(navigator.userAgent)) && (window.navigator.userAgent.indexOf("Windows")!= -1) ) {
var URL = "https://web.whatsapp.com/send?phone=";
}else {
var URL = "https://<?php echo $waurl;?>.whatsapp.com/send?phone=";
}
into this :
if ((/Firefox[\/\s](\d+\.\d+)/.test(navigator.userAgent)) && (window.navigator.userAgent.indexOf("Windows")!= -1) ) {
var URL = "https://wa.me/send?phone=";
}else {
var URL = "https://wa.me/send?phone=";
}