If you go to the HA integration for the Bond Bridge, then click on the relevant fireplace’s entity, does it show up as active and, if so, does it respond correctly from there?
I have looked in my HA logs and the integration’s diagnostics and cannot see any reference to my devices (i.e., entities) as URL’s like you describe. That does not mean it is not accurate of course.
I would try removing the device from the Bond Bridge app, then adding it once more, and seeing if the entity responds correctly in HA.