Prevent a button opening a modal if another button has not been pushed first

I have a modal that opens with data and another button that lets people see that same data again at a later stage. The only thing is, if the user clicks the button to restore that data, before the data has been applied, the modal opens empty.

So far I have this idea to prevent that button opening an empty modal, but not quite sure how to execute it.

Button withData == Pressed:
  dataPresent= True

if dataPresent === True:
  [what goes here? I want the modal to open as normal]

Button withoutData == Pressed:
  dataNotPresent = True
  dataPresent = False

if dataNotPresent == True:
  [don't open the modal]

I could also add an attribute "disabled" – but again, not quite sure how I put the syntax together (yet).

So the last line could become something like this:

if dataNotPresent == True:
let btn = document.getElementById("myBtn");
    btn.setAttribute("disabled", ""); 

I am very much a beginner here, so this may seem trivial (but not to me). I appreciate your help and I do select right answers too 😉

let buttonA = document.querySelector('button.first') // looks for <button class="first">
let buttonB = document.querySelector('button.second') // looks for <button class="second">
let modal = document.querySelector('.modal') // looks for first element with class="modal"

let buttonAPressed = false

buttonA.on('click', function() { buttonAPressed = true })
buttonB.on('click', function() {
    if(!buttonAPressed) return
    modal.style.display = 'block'
})

let currentScenario = document.getElementById("current-scenario-1");
  currentScenario.removeAttribute("disabled");