There are some profiles on Instagram where you want to see the content they publish as soon as possible - it could be a news page or your favorite blogger. See how you can receive notifications for new posts, Stories, IGTV and Live.
You can turn on notifications for new activity and posts per Instagram account.
Here, tap the notification icon (bell) in the upper right corner.
From here, select the “Recieve All Notifications”.
When there is new activity from this profile, you will look a notification for this on your smartphone.
This feature is available in specific countries, so you may not see the bell to activate notifications for each profile!
Source of information: howtogeek.com