The /lab-inbox URL is a redirect that ends on the People page. There is no separate Lab Inbox popup or tool. Comments and @-mentions surface inside the record popups where they were posted, and lab-wide announcements from the PI appear behind the Announcements button on the People page.
Where comments appear
Comments are attached to the record they were written on, not gathered into a shared inbox view. Open a task, note, or purchase and the comments rail opens on the right side of the popup. The PI badge, the author name, and the full thread all appear in context next to the record body. See Comments for threading rules, @-mention behavior, and how to open the rail.
Where @-mentions appear
When someone @-mentions you in a comment, the mention pushes a notification to your bell, and to your laptop, phone, or email if you have turned those channels on in Settings. The mention is always readable in context by opening the record the comment is on.
Where announcements appear
Lab-wide announcements from the PI live on the People page, behind the Announcements button in the page header. Click it to open the stream. PIs also see the composer at the top of that section and post directly from it. Members see the announcement stream by opening the same button, or when an announcement notification lands in their bell. See Announcements for the full posting, pinning, and edit flow.
Where to go next
Comments covers threading, mentions, and the in-record rail.