Please ensure you are signed in under the same Glo account in which you created the data.
As you are inside the app click anywhere on the screen and a menu icon will come up(top left corner ) Press it and then Press the profile icon and you will see the option to login.
Your data such as bookmarks, notes,highlights etc. will be available in the Notepad section of the app. To navigate their , tap anywhere on the screen and then press the Notepad icon at the bottom left of screen.