get https://externalapi.retailrocket.net/api/3.0/productRecommendations/relatedByPreferedSize
The algorithm returns related product items with priority for products that have in stock the size that interests the user. For the algorithm to work, it is necessary that additional information being passed to the product's "size" parameter.
Link
linkconsists of a name and a value, in the query string the name and value are separated by a comma, example: link=card,12345, where card is the name and 12345 is the value.