1) In order to use the new Instagram Hashtag API you must first have an Instagram Business Profile. See here for directions on how to convert a Personal profile into a Busines profile.
2) Once you have a Business Profile, use the ‘Connect an Instagram Account’ button on the plugin Settings page to connect it.
3) You can then display your Hashtag feed just like before; selecting ‘Hashtag‘ on the settings page, or using
type=hashtag in your shortcode.
Known issue: A bug in the new Instagram Hashtag API is currently causing an issue for some Instagram accounts and returning the error “The requested resource does not exist”. Please see here for more information.