There is a new interface update in Chapters: Interactive Stories.
Previously, you can access your friends invitation code, events and special from the floating balloons/ presents located at the bottom right of your homepage.
This has been removed from the latest update and the section can now be found as the present icon (4th bottom tab from the left) in your homepage, as shown below.
When you click on that present icon, you can access both Events (circled in blue) and Special (circled in pink).
It is also where you can find your April check in calendar.
I will also update my Chapters Interactive Stories invitation code post with this new update soon.