There are three main requisites to connect Instagram to Google Looker Studio or Google Sheets to build a dashboard:

You should grant access to all the Facebook Pages and Instagram accounts to Porter Metrics in order to retrieve their data. Visit this authorization link to refresh or re-authorize your Instagram connection with Porter Metrics.
The Instagram Business Profile must be linked to a Facebook Page.
You must have a role with enough permissions such as editor, analyst, or admin to your Facebook Page.

Instagram reporting limitations

The Instagram API has some limitations when it comes to retrieve historical data.

Instagram Stories data are only available since you connect to Porter

Instagram Stories are only live 24 hours on the API, which means you can only access your Instagram Stories data since the moment they're connected to Porter Metrics as we're storing the data for you.

No historical data from Instagram Stories is available before connecting to Porter Metrics. You should make sure you've granted access to Porter Metrics to access your Facebook profile by checking the authorization.

New Followers and Profile Reach historical data show up to 28 days

Since you connect Instagram with Porter, you can only access the past 28 days of historical data for New Followers and Profile Reach.

Once connected, Porter stores your data so you can mitigate these API limitations in the future.

Daily Total Followers are only available since you connect to Porter

The Instagram API doesn't store historical data for the field "Total Followers" as it only retrieves its last value.

However, Porter stores your daily total followers since the moment you connect so you can track Iinstagram Following growth over time.