The ShopMessage Checkbox widget will display on any device's browser (desktop, mobile, tablet) when the user who is viewing your store is logged into Facebook within that browser session.
If the user is not logged into Facebook, the Checkbox will not show up in that browser. This is intentional because the goal is to keep the user within the purchase flow, and having them log into Facebook can be interrupting and cumbersome, especially on a mobile phone.
Some scenarios to consider:
The Checkbox isn't showing up on my iPhone, what gives?
In the latest versions of iOS, the default Safari setting is “Prevent cross-site tracking” set to True. When this is set to true, the Messenger checkbox will not load.
Will the Checkbox show up on my on my mobile browser if I have the Facebook app on my phone?
Not necessarily. The checkbox shows up if you are already logged into Facebook on your mobile browser. You can test this by navigating to www.facebook.com within that browser and seeing if you are logged in.
What if a user clicks my link within the Facebook app?
If a user lands on your page within the Facebook app they will see the checkbox widget display.
Will the checkbox show up in Instagram?
Instagram's browser does not automatically log users into Facebook, so they will not see the checkbox. We are hoping that Facebook changes this in the near future.
Why isn't my checkbox showing up on Safari?
Facebook has temporarily disabled all Messenger plugins on Safari 12. You can read more about this here.