JSFiddle - React, Tailwind, and code Playground

HTML

<input id="inp__str_Object__17" type="checkbox" name="inp__str_Object__17" sym_name="Cust_attr_1" value="400024" >

JavaScript

var elem = document.getElementsByTagName("input");
var id = "";
for(var x = 0; x < elem.length; x++){
    if(elem[x].getAttribute("sym_name")){
       id = elem[x].id
    }
}
alert(id);