Help Salem Overcome Kidney Disease

Salem is my kitten, I adopted him because since I saw him, my heart was racing, he has been my partner in these almost 24 months of life that he has, he is my baby and a few days ago he began to stop eating, I took him to the vet for emergency and they found an ulcer in his mouth. They medicated him and he began to get better but days later he got worse. Now they tell me that his disease is kidney problems and I should hospitalized him to determine the real state of the disease, and know if there is treatment or it is terminal illness.

I need your help to be able to admit him and carry out the studies I don't want to put him to sleep without giving it a chance. I want him to recover to see him jump and purr when I get home, run when I put food on his plate. Help me give Salem a chance of life.