You can try to edit js/mega-superstorefinder.js (if you’re using add-on. i.e marker clusterer add-on, edit wp-content/uploads/ssf-wp-uploads/addons/ssf-marker-cluster-wp/mega-superstorefinder.js instead)

search for

_store.website,

and change it to:

 _store.website.replace(/(^\w+:|^)\/\//, ''),

Save and upload the file and clear browser cache.

At frontend end, http:// or https:// will no longer be shown in front of the website