Go to the workspace and click "Settings & Members" then "Manage members"
"Settings and Members" can be found at the top left in the sidebar. "Manage members" is an option under "Settings and members".
Find the user you'd like to make an admin
You should be able to find their name in the "Members" list, which you can search for the user by name or by email. If the individual hasn't been added to the workspace yet, you can type in their name to invite them.
Click on the drop-down menu and select "Admin"
Click "Update" to confirm the changes
Make sure you update your changes so they take effect. The new admins will have access to workspace analytics, settings, and members effective immediately.
Once you click update, you can choose whether Flint sends an email notifying the individual that they've been invited to the workspace as an admin.