Thanks for posting in the community! Just to make sure we're on the same page, please review our Offline Mode article that includes instructions on how to set it up. Under account settings, you want to look for "Offline Settings" tab in the left-hand column.
Please note that right now Chrome and Firefox are the only browsers that support offline mode. If you are using one of these browsers and still not seeing the Offline Settings tab, please try accessing your account in an incognito/private window. Hope this helps!