Legacy login and personal access token not available in profile

Morning all - So I’m attempting the start of this ShotGrid migration malarkey and already hit a speed bump. Well, two actually. Not only is the link explaining about migration not working but also under the instructions for adding the access token to my existing shotGRID profile- the option isn’t there. It’s supposed to be underneath “My following settings” but isn’t showing up. Any advice on that one?