Can't you find all the symbols on the Naver Korean keyboard?

Hello. While using Naver Korean dictionary, I find myself unable to locate all 40 symbols, including 19 consonants and 21 vowels. When I tried using the Naver keyboard, not all symbols appeared. Why is that? Has anyone who is a foreigner experienced something similar in Gangnam or Hongdae? Comparing to the Naver keyboard, it seems like all symbols are visible on [this site](https://www.lexilogos.com/keyboard/korean.htm). I am curious about what the difference is. Is there any way or tips to solve this issue? Any advice would be appreciated.