Retrieve sessionStorage variable mid way through a multi-step popup form

I would like to retrieve the value of a sessionStorage variable that was set in step 1 of a multi-step pop up to help in the conditional display of text in step 3. All five steps sit within a form and every post is handled by AJAX routines and are working fine.

Does anyone have any ideas about how I can pass the variable (selectedRole) back through to the front end from AJAX so I can use it in step 3?

My code to save the variable is as follows:-

    function setUpPopupRegistrationForm() {
        
        $('.js-popup-register-button').on('click', function() {
           
            let storage = window.sessionStorage;
            let selectedRole = this.dataset.role;
            
            storage.clear('selectedRole');
            storage.setItem('selectedRole', selectedRole);
            
            navigateToNextStep(this);
            
        });
        
    }

<div class="form__step js-popup-register-step" data-step="1">
  <h3>
    <?php the_field('title_1', 'option'); ?>
  </h3>
  <div class="d-flex flex-column flex-sm-row justify-content-between">
    <div class="button button--blue js-popup-register-button" data-role="member"> <span>Member</span>
    </div>
    <div class="button js-popup-register-button" data-role="guest"><span>Guest</span></div>
  </div>
</div>