1. Run Rapise Npm Console and run:
npm install deasync
2. Wrap you call in a function like that (it calls AsyncLibraryCall and returns the result):
function DoSomethingSync()
{
	var deasync = require("deasync");
	var result = undefined;
    var completed = false;
	
	async function asyncOperation()
	{
		result = await AsyncLibraryCall();
		completed = true;
	}
	
	asyncOperation();
	while(!completed)
	{
		deasync.runLoopOnce();
	}
	return result;
}
3. Note: You must use NPM console from Rapise, because Rapise has own runtime.