Help for Tyr

We found this kitty injured on the street few months ago. We have taken him to the vet many times to find a solution but finally they have to amputate his leg. Tyr is very happy at home and he has a very cheerful brother now! But due to the covid situation we have been left without work and we cannot afford the cost of the surgery.  Now he has a fever and he is not even eating as he did before. If we don't treat as soon as posible he can get worse. So if you can help even with a little amount of money to reach the cost we will be really relieved.