How would we get values in Preline Tailwind CSS ComboBoxes whenever selection updated?

I’m using pure HTML+JS+PrelineCSS and I have this code copied from here Example 1 a basic usage of ComboBox its working perfectly, however how would we get the value of the input whenever it changes? the value is always empty when we change selection unless it gets the focus!

I tried this <svg onclick="testValue2()" to force the input refocus:

function forcefocus() {
    document.getElementById("input1").focus();
}

It is working but it gives always the old value which means it is not ok! :s

Is there away or different approach to get the value on a function like this <input onblur="testValue(this)":

function testValue(el) {
    console.log(el.value);
    console.log(document.getElementById("input1").value); 
} 

The aim here to ( get the input ) then verify it before using/posting. So how would we get it please?