HTML Add or multiply two numbers

[thehen]

Good day

I am trying to get a total of two numbers.
The first number I need to get form my page (the number changes every few seconds (crypto clicker)
Second number will always be 35
This is the code I got after search, but do not know how to get it to work

     <form>
            USD:<input type="text" name="num1"><br>
            Doge:<input type="text" name="num2"><br>
            Sum: <input type="text" name="sum"><br>
            <input type="button" value="Sum" onclick="calcSum()">
      </form>
<script>
           function calcSum() {
        let num1 = document.getElementsByName("num1")[0].value;
        let num2 = document.getElementsByName("num2")[0].value;
        let sum = Number(num1) * Number(num2);
        document.getElementsByName("sum")[0].value = sum;
    }
</script>`

 

[Mutiny]

When you try to run it does anything happen? If you open your browser's console (right click, hit "Inspect" and then go to "Console") do you get any errors?