I finally installed YOURLS on server. I got $50 at Digitalocean using GitHub Student’s pack. I bought a server first then register a free domain at Namecheap. I found one with name urlslice.me. And finally it’s working.
Now I decided to create a logo for urlslice.me. Then I have to edit Yourls Firefox and Chrome extensions with my own logo and name. After that I will edit the webpages design of Yourls.