How can I show an image of Recommendation records that are generated from Recommendation Builder on Next Best Action component?

My problem is just described as a title.

I am struggling to show an image of each recommendations that are generated from Recommendation Builder. 

The image on recommendation should be used `ImageId` field on recommendation object, so I created an enhanced apex class to add each `ImageId` with `ContentAssetId` but I have still no luck.

Does anyone successfully display an image on the same situation?