You can invite users to collaborate on a styleguide with you. This will also generate a link to the styleguide, which you can share with them.
Adding a member from the styleguide's Dashboard
To invite a member to a styleguide, go to the right panel on the “About” page of the styleguide then click on the “Share” button. Enter the email address associated with their Zeplin account or their username and click on the “+” button:
There, you will also be able to copy the Web or App links. Those links can be shared with anyone invited to the styleguide and they will be able to access it in Zeplin.
Adding a member to a styleguide from the Styleguide list
You can invite members from the Styleguide list, by hovering over the styleguide thumbnail. Click on the settings icon and select “Invite…”: