You can't. I just called them today and they told me that it can only be added when you order the tablet. When I ordered mine there was a statement that you could add it up to a year after purchase... But the agent claimed that was just for phones. Misleading website or I would have ordered it then.
** If my response helps, please click on Like (Heart). If I resolved your issue also please click on Accept as a Solution so that others can benefit.
Bill --- Galaxy S21 Ultra 512g(VZW), Galaxy Book (original, VZW), Tab S8 Ultra, Tab S4, Galaxy Watch3 (VZW)
