There is a number of solutions in Linux like this one, but the consensus seems to be there is none for Windows. See e.g. here or here (scroll to the bottom)

In Unix or Linux you can use the:

system clear

Also you may try to use Ctrl + L in linux

However if you are using Windows then I think it is not possible. You may refer to this bug which is reported for the same for windows.

The only best think I can think of is you can only Exit MySql, Type CLS and then re-enter MySql.

Try \! cls; worked for me on Win 10, MySQL Command Line Client 8.0

Are you using a Unix client? Try Ctrl + L. Might even work on Windows too ...