missing producerId.

I’ve built a visual studio 2017 c++ project using libmediasoupclient library.

And everything was ok until creating sendtransport and recvtransport.

But when I create server side consumer, it failed.

json body =
{ “producerId”, ProducerId }
auto r = cpr::PostAsync(
cpr::Url{ this->baseUrl + “/broadcasters/” + this->id + “/transports/” +
this->recvTransport->GetId() + “/consume” },
cpr::Body{ body.dump() },
cpr::Header{ { “Content-Type”, “application/json” } },
cpr::VerifySsl{ verifySsl })

status code:400
Type Error:missing producerId.

I’m using other peer’s producerId, and I’m sure that there is no problem with producerId.

What is the reason?
Help me.

That’s a custom code, I can’t help here.