If you're not a member of a geekbuying affiliate program, you can join here
Navigate to your geekbuying affiliate
There you can find "Standard linking code" and link that looks something like this:
Number at the end of the link is your affiliate ID (in this case 1315)
All you need is to copy that Affiliate ID, open extension options, go to Platforms / Big Chinese stores, and paste Affiliate ID in the geekbuying field.
Then close options, find the product on geekbuying you want to share and click on the extension icon. It will generate an affiliate link for that page. Then you can use bit.ly to shorten that link (if configured) or copy and share it.