I have Google Workspace Business Starter plan and I want to create spaces with other external team members (with other workspace users). Is It’s possible.
People outside of your organization can join is disabled.
From admin panel it is allowed to send message outside the domain.
In your second screenshot, notice the text right above the checkbox: “External membership settings can only be selected when a space is created.”
Even if your Admin has allowed external chatting in the Admin Panel (as you mentioned in your third post), Google Chat doesn’t allow you to flip this switch on a Space that already exists. It’s a security feature to ensure a private internal Space doesn’t accidentally become public later on.