There are 2 options
1. You can use our OAPPS for Instagramer Comments&DM app on FreshDesk Marketplace. Currently DM option is in beta. Please contact our support if you want to participate in beta. To use this app you will need your Instagram account to be connected to your Facebook page.
2. You can use our OAPPS for Instagram DM [in development] option that uses private API and emulates Android app connection.