Open the Instagram app
Tap your profile picture
Tap the menu icon
Select Settings and privacy
Tap Notifications
Choose the notification type you want to change
Adjust the notification settings available in Instagram
Open your phone Settings if you want to change the sound
Tap Apps or App notifications
Select Instagram
Tap Notifications
Choose the notification category
Tap Sound
Select a new notification sound
Save the changes
Make sure your phone is not on silent or Do Not Disturb mode