To be able to show an Instagram feed, you need to retrieve your own user id (this is something different than your username/handle). The reason why you need this ID is because of Instagram's security, called oAuth. You can find your (or any other) ID here.
Enter this id in the field Instagram ID on your profile.
If entered, your feed will show up on your profile like shown below.
Please note: your profile must be set to public to be shown.
Error: No connected account.
Please go to the Instagram Feed settings page to connect an account.