Web Lookup app does not appear in the Advanced Tab

Hi,
 
I installed the Web Lookup app in both 2015 and 2017 SDL Trados versions but I cannot find it in the Advanced Tab. I can only find it when I right click after selecting the word.
 
How can I display the Web Lookup app in the Advanced Tab please?
 
Thank you for your reply
 
Kind regards
 
Nadia