Need image editing Help !!!!

Hello,

Thanks for checking my post, I need help in editing this picture, there was no light while I clicked this picture and i dint want to use flash as it might be harmful for his eyes. 

I can't take another pic, because this cat died in a road accident, sadly this is the only pic i have of him ☹️. He isn't my cat he's a stray cat. I have the habit of framing my lost pets pics I want to frame this cat's picture too because this is the first cat I touched, and he's the first cat who allowed me to touch/pet/play/ fuss him I'm actually a dog person never been or touched cats. He's close to my heart. Please help me in brightening this picture 🙏. Let me introduce him to you he's LEO.