In order to see the chat bubble,
1. You have to chat during business hours: every day from 8 a.m. to 9 p.m. (EST).
2. Disable ad-blockers. Also try clearing browser cache and try using incognito/private mode.
3. If problem presists, try using a different browser on your computer.
Note that once you have resolved steps 2 and 3 and get the chat bubble, you should also retry the activation, because it's likely the same browser issue was preventing the activation.