Does anyone know how to get a VWAP indicator to work in a python algo?

Below is the only way I've tried that doesn't give an error. This also never seems to have a value other than 0.0, and it is never marked as IsReady. Any ideas what I'm doing wrong?

For the symbol, I'm pulling tick data (forex), and I'm also consolidating the data into hourly bars.

Thanks in advance!

self.vwap = VolumeWeightedAveragePriceIndicator(self.symbol, 20)