Hi Moshe,
nowadays, questions about integration scenarios (like calling WA from PB) should be rephrased from "can I use XXX service from PB?" to "does XXX service offers REST API?".
If answer to 2nd question is affermative, then PB (and PowerServer) offers you a large set of objects to deal with API calls (HTTPclient and RESTclient in order of importance and flexibility) and data handling (most likely in JSON format, thereby JSONpakage, JSONparser, JSONgenerator will be your friends).
Quick Google search:
Best,
.m