ShopBack Button may not be available for all merchants as it requires the merchant's approval. If it does not turn green on the merchant's site, it means that it is not supported by the merchant.
Therefore, it is advisable for you to click from the ShopBack website to the merchant's page for cashback eligibility.
NOTE: At the check out page during payment, the ShopBack Button will turn red as tracking cookies would not go through during payment process for security and privacy purposes
Also, if you have any adblockers installed, do note that the ShopBack Button will always maintain in red due to tracking cookies are blocked!