In the PCBI 365 design tree you have many options, one of them is to share the design via link for PCB-Investigator users:
Use "copy link to clipboard" and send the link to other users, if they have an PCB-Investigator installation on there machine it directly opens the design from the 365 cloud storage.
For user without PCB-Investigator installation, there is a second button to share data in online viewer:
1) Open the 365 Explorer and navigate to the design data you want to share via online viewer
2) is the PCB-Investigator sharing link
3) is the online Viwer sharing link
Here is a short video to show how to get the sharing link for PCB-Investigator users with access to the 365 data:
And a second video to show how to use online viewer share function: