Step 1:
Click on your account name to expand the menu on the bottom right corner of your screen → select Team Members

Step 2:
Add your team member's email address → You can choose to invite as an admin/editor/guest → select invite.

Be sure to select the workspace/s you would like to allow your team member/s to gain access to.

Step 3:

You can manage your team member's access here ↓

Step 4:

You can manage your guests or upgrade them to team members here ↓

➠ For quick access to your team members/guests, click on the drop-menu on the top right corner of your screen: