If you're a team owner in Streak, you can add users from the Teams page. Adding somebody to your team gives them access to pipelines shared within that team.
Navigate to the Home page by selecting "Home" from the left navigation menu or the Streak icon at the top of your inbox and click the credit card icon in the top right corner to access the Billing and Teams page.
To the right of Members, select "Add/Remove Team Members."
This will open a new window with your current team displayed on the left side and your future team on the right.
Enter their name or email address into the field at the bottom of the right side and click the Add button.
Click the Continue button.
Confirm and click "Save Changes"
Once you’ve added the new teammate, they’ll need to download the Streak extension in their inbox. Upon adding them, they’ll receive an invitation to join your Streak team at the top of their inbox. To manage the pipelines you want this teammate to have access to, modify their permissions inside each pipeline.