Google Ads targeting audience from specific youtube channel?

I want to promote my video ad to a specific Youtube channel. I already tried to select that youtube channel as a source, based on Google ads my ad should be shown on videos that are posted on that channel. The problem is that it does not work because youtube channel I'm targeting does not have enabled monetization.

No matter what bid I set it has 0 impressions. The video ad is approved and active but no impressions at all. The youtube channel I'm targeting has about 20k subscribers.

My question: is it possible to target that audience/subscribers from that channel that no matter what video they are watching my ad shows up? Is there an option for this besides of keyword targeting?

It would be nice if that was possible but it's not unfortunately.

In this circumstance the only way you would be able to target the exact people watching and engaging with that channel is if your ads account was granted access to the channel, then you could make use of remarketing audiences.