Instagram Insights requirements are usually baked into a collaboration brief. But there is a way to still request for Instagram Insights when a collaboration doesn't require a brief. See walkthrough below:
How to Request a Member to Link Insights
Go to the creator's member profile.
Click Actions at the top right, then choose Upload Content, then select Social Post. From there, click Account Verification and select Ask to Authorize.
This is optional, but you can make necessary changes as needed.
Select Preview and review the email.
Once done, click Send