Can Workplace support Just-in-Time provisioning via SSO?
No, we don't take SAML attributes and provision users. However, you can use self invite, or one of these provisioning methods.
To mimic partial behavior of Just-In-Time provisioning, you must ensure that single sign-on is enabled and Self Invite is on. Once you've made sure your community's settings are updated with those changes, you can create a SCIM-based user management/connector app.