Please go to "Settings" by tapping the two-lined button in the upper left corner of home page. Tap "Settings" and see the option "Restore purchased items". You can restore all the content you have purchased and subscribed to by tapping the button.

Or you can go to sticker store by tapping the icon in the bottom right corner and see the tab "My items". In the tab, you can see a "Restore purchased items" button and by tapping it, the content you subscribe to will be restored.