If you find that something is not showing up in your left navigation, i.e. a setting or admin page, then you will probably have to install the Add-on in the Add-ons section.
- Below the Integration section is missing the (API) REST option
- Check in the Add-ons section of PI to see if it is installed or not
- Follow the My Insight menu to "Add-Ons"
- If under "Installed" you might need to fix a Configuration, if under "Get More" go ahead and install!
- Now I installed the "REST API Access" Add-On, the option will now appear in the left nav