You can invite someone to your workspace even when they are not from your domain. You can invite them through their email ID with restricted or complete access to the property data, depending upon their role and contribution

To Invite an admin, a creator or a viewer, click on the invite icon on your property dashboard.

Enter one or multiple email separated by a comma. Select what role you want to assign them that is- a creator, an admin, or a viewer. You can read there what each role gives access and restrictions to. You can also restrict their property access under the data access section.

Click Send Invite to invite them to SiteRecon.

Or you can also share your organization's code which they can paste into their invitation pop-up.