Steps: 1) Go to "RELATIONSHIPS → Buyer Management" and click "+ Add Buyer". Fill in basic information such as company name, contact person, and email. 2) Enter the buyer's detail page and click "Send Invitation" or "Copy Invitation Link". 3) The system sends an invitation email, or you can share the link with the buyer yourself. 4) After the buyer accepts the invitation through the link, the status automatically changes to "Invitation Accepted" and they can use buyer-side features. You can track the invitation status at the top of the detail page.