They should be requested by towns. Due to the amount of products in this mod it is possible that not enough randomly generated towns are available to request all goods. What map size and town density are you using? As I said in the description, you need to have the largest (non-experimental) map possible and high density to fit everything. Or you could use sandbox mode to add or change towns.

Also sometimes it's a bit hard to see on the game map. Have you checked the consumers list of the factories? If a consumer is available, you can click the map icon and it'll take you to the consumer on the map.