Content-Type:application/x-www-form-urlencoded;charset=UTF-8
Content-Type: application/json; charset=UTF-8
var_dump(unserialize('timestamp|i:1550665420;current_language|s:1:"1";current_currency|s:1:"3";comprlist|s:5:"14322";'));
// bool(false)
var_dump('timestamp|i:1550665420;current_language|s:1:"1";current_currency|s:1:"3";comprlist|s:5:"14322";');
// string(95) "timestamp|i:1550665420;current_language|s:1:"1";current_currency|s:1:"3";comprlist|s:5:"14322";"
Нужно передать вот это
post запросом на адрес /ipp/v2/payment/create
с заголовками
Accept: application/json; charset=utf-8
Content-Type: application/json; charset=UTF-8