It does look like bumblefoot. Usually you will see a lesion on the bottom of the foot, that's where the injury generally happens that lets the bacteria in, but yours looks like it started on top or between the toes. I would treat the same way as usual, you will just be working from the top where the scab is. This is generally what I do: https://www.tillysnest.com/2015/12/non-surgical-bumblefoot-treatment.html/?spref=pi