Please Help me Save Simon

Hello, Simon is a 12-year-old Miniature Schnauzer, he is the most playful thing and arrogant at same time, he is just lovely, after the second dose of the COVID-19 vaccine, John T, his owner died, leaving the dog behind, Simon has various tumors, one under his lower mandible, making it hard to eat, the other is under his right front leg pit, both tumors are growing in size, making it hard to walk, run or bath,sleeping has become hard for him the high prices of medical treatment make it impossible for me to take him to a vet, to get proper medical treatment for Simon, I must ask for help, I don't want him to be euthanized, since he still very much alive, I ask for basic vet help, the doctor's appointment, the lab, and surgery, it's like 1600 dollars, I am from Tampa Bay, but Simon is in Medellin, please help me save Simon.