Invite the user to your workspace by email.

In the Add to libraries modal, select one or more libraries to add the user to.

Select Invite to send the workspace invite and add the user to the selected libraries.

Hover over the library name to show the ⠇edit menu

Select the ⠇edit menu

Select Invite members

Under Invite members, activate the member list to drop down a list of users that can be invited to library

Select user(s) to invite

Review / modify library member access level

Select blue 'Invite # users' button

Select the Edit menu in the header next to the library name

Select Invite members

Under Invite members, activate the member list to drop down a list of users that can be invited to library

Select user(s) to invite

Review / modify library member access level

Select blue 'Invite # users' button