javascript - Difference between input change and manual input

Question

At work we use a program that allows us to create html forms to use with their mobile app. The form allows javascript, however, upon submission any element content changed using innerHTML property is erased and the default content is the whats submitted (blank). I have been searching for a work around and noticed if instead I use an input as the element and change its value with javascript, upon submission the changed value will not be erased if the user clicks into and adds one more character

My question is how does the submission button differentiate between a changed value via js, vs a manually inputted value? And is there a property I can use to make the form think a value was inputted manually?

I am limited to what the app allows me to do, i am unable to change anything about the submission button

example

function addElement() {
    document.getElementById('div1').value = "Changed Value";
}
            

<div><button onclick="addElement()">Button</button></div>
  <input id="div1">

question from:https://stackoverflow.com/questions/65925790/difference-between-input-change-and-manual-input

Answer 1

Waitting for answers