You can blur from inside the Moderator, you click B (from Bluro) to enter Blur mode and then you can draw blur rectangles. Once you are done, Save and publish the tour to Google Street View. GoThru will auto blur the images at publishing time.
Please also check this tutorial, where I am explaining how to blur inside the Moderator:
https://www.youtube.com/watch?v=Bt8rvy6qAGM&t=19s