JSFiddle - React, Tailwind, and code Playground
HTML
<label class="intro-header" for="form-field-1"> Amount </label>
<label>
<input type="text" id="amount" placeholder="" onkeypress="return isNumberKey(event)" maxlength="10" />
</label>
JavaScript
function isNumberKey(evt) {
var charCode = (evt.which) ? evt.which : event.keyCode;
if (charCode != 43 && charCode > 31
&& (charCode < 48 || charCode > 57))
return false;
return true;
}