خیلی سادس این کار.
Sub sendPushFCM
Dim prf As PersianFastNetwork
prf.initialize("prf")
Dim postQuery As PostRequest=prf.BuildPostQuery("https://fcm.googleapis.com/fcm/send","fcm")
Dim prj As PersianJSONOBject
prj.initialaizJsonString("your json hear")
postQuery.addJSONParametrs(prj.DefaultJsonObject)
postQuery.addHeader("Content-Type","application/json;charset=UTF-8")
postQuery.addHeader("Authorization","your key hear")
postQuery.executRequest
End Sub