JSFiddle - React, Tailwind, and code Playground

HTML

<input id="myinput" type="text" value="館 gg" />
<input type="button" onclick="removeSpecials(event)" value="test" />

JavaScript

function removeSpecials(evt) {
    var input = document.getElementById("myinput");
    var patt = /[^\u0000-\u007F ]+/;
    setTimeout(function() {
         var value = input.value;
         input.value = value.replace(patt,"");
    },100);
}