If you want to collect Instagram content (@mentions and hashtags) from other people you must first connect and authenticate your Facebook account on the Miappi dashboard's Feeds page (see section 1. 'My Feeds'). You will also need to connect your Instagram Business account.
Connecting Instagram for Business:
Create an Instagram account (skip this step if you have a Instagram account)
Convert your Instagram account to a Business account (skip this step if you have already converted to a Instagram Business account)
Create a Facebook Page (skip this step if you have a Facebook Page already)
Link your Instagram Business account to a Facebook Page
How to associate an Instagram Business profile with your Facebook account.
Whoever connects your company's Facebook account will need to be a page admin on that account. You will be asked to enter your personal username and password.
Once Facebook is connected you can then connect 'Instagram Graph' and choose the relevant Instagram page.
To find out more about what Facebook/Instagram have announced here's a link to their official Developer News page.
If you are using Instagram for business we recommend you convert to a business profile. How to set up a business profile on Instagram.