JSFiddle - React, Tailwind, and code Playground
HTML
<input type="text" id="txtCont"/>
<input type="button" class="btnfetchcont" value="Get contact"/>
JavaScript
$('.btnfetchcont').on('click',function(){
var value=$('#txtCont').val();
value=value.replace(/^(0|\+\d\d) */, '')
alert(value);
});