Please identify this coin

I wasn't sure how to post on your forum, so hopefully this goes through.  At first, I thought this was a coin from China, but after browsing through your website, it may be from Mongolia.  Thanks for any help.

Hi!

Search in southern korea

Thanks!  I will search in South Korea.

Take a look here : https://en.numista.com/catalogue/pieces1037.html
 

Thanks, monéphil and fred24.
My 'mystery' coin was in South Korea.  And at that exact url.  Now I know what I have.
I am not a coin enthusiast as the rest of you are.  You sure do know your coins.  I just find the coins interesting.  The way I've obtained them is either finding them on the ground, or given a non-USA coin in change on a purchase.  No, I don't return it.  I just keep it.
I have a question, can someone submit a picture of a coin that isn't on this website?  Even if the person doesn't buy, sell, or swap?  I found similar to the coin I have, but the website's pictures are not exact.

  Yes - you can send in a picture, and if the coin is not on here (or is a better picture than one already on here) then usually we can add it. Thanks, and welcome to the site.  

Thanks, ZacUK.
Here is the coin that matches some Russian coins on your site, but has some differences.  I hope the two images come out the same size.  I don't know why the last images I uploaded, came out different sizes.  Different kilobytes, perhaps?

20 roubles Russia
https://en.numista.com/catalogue/pieces4077.html