I'm sorry your budgie has broken his toe.
If the budgie was more prone into falling due to the disability on his foot and this was clear early on into having him, it would have been best to take him out of the aviary and place him on a cage and adapt the cage to better accommodate his needs. With time you could have also worked on taming him.
If by now you think your budgie will be too stressed to be placed in a cage, then the second best option would be to confine the area in the aviary (or place a cage inside the aviary where your budgie could be safely in).
You will need to pay a very close eye, because other budgies can start to bully him because he is currently more fragile.
Given the severity of the case, finding an emergency clinic that offer avian vet services would be the best course of action. Your budgie needs to be seen asap.
If the toe happens to be amputated, your budgie will soon adapt to the change.
Budgies (and other pet birds) are quite resilient and with our help and support they can overcome even greater obstacles.
I'm wishing your budgie all the best and hope he will soon be on the road to recovery.