Like someone said above, the best option would be to check if the streamers that you are looking for have business emails, if they dont maybe check if they have a twitter or discord and ask them there.
Furthermore, if you are talking in there chat, ask there if you dont mind others knowing what you are saying.
I think that the best option would be to ask in chat a simple version of what you are asking, and if they would like to know more then ask them to whisper you or message you on another one of their platforms.