I made a weather web application using tkinter library. However whenever i am trying to publish it on github pages or other web hosts, it get 404 error.
I tried pythonanywhere by anaconda as well and still couldn’t publish my application
No, tkinter isn't designed to work on a website. With a tremendous amount of engineering it might be possible, or by using third party websites*. At its core, though, tkinter requires a display, not a browser.
* repl.it makes it possible to run tkinter code, though I don't think it's suitable for making apps. It's good for experimentation, though. I've seen one or two other solutions for running tk on the web, but they are very specialized and generally don't let you create apps that work like a traditional.