Mentions were earlier available only for Instagram comments.
Instagram DM mentions is now on Crowdfire! :)

Where can I access Mentions?

You will find it in the top bar under "Mentions"

You will be able to access Instagram DM Mentions within your Crowdfire dashboard where you currently see Twitter public mentions and DMs, Instagram Comments and Facebook page messages, Facebook page comments.

Note: This feature is only available for Instagram accounts that have access to Instagram Messenger APIs.
It's also phased rollout and isn't available for everyone at the moment. Keep an eye out though.
It's coming soon :)