I'm getting mixed results on this and would like to know for sure.

I'm not talking about a link to circumvent Amazon, like a link to a site that sells other products but what I want to include is strictly for support and to help customers with the product. If it's not allowed on the listing itself, can I include it in the product insert. I watched the video about the inserts and it wasn't completely clear to me.

I wouldn't tell customers to go to the link but I would tell them if they needed help they can go there for support. I'm thinking of either a forum or discord server, or a FAQ website, or one or more Youtube videos that show how to use the product, or if possible a combination of those.

Btw. as a buyer I'm struggling with a product (it's a wheelchair for dogs and I'm not sure that I have it set up right). I wanted to send pictures to the seller and ask them if I'm doing it right but there is no way to contact them and I did not see any links anywhere so I'm actually going to return it. If at all possible I would like to avoid this with potential customers of my own product and provide as much support as possible including the things I mentioned. Any clarification would be very much appreciated.