Where/how to market my science videos, especially in China?

Well, I'm almost ready to 'hangup my hat' with teaching mostly primary grade science 'online'.  I've been doing this successfully for many years, but as I grow older, I assume that the number of young students who want to learn from an eccentric old man will diminish....

For that reason, I have been creating learning videos of the complete primary/elementary science school curriculum, from grade 1 to grade 6, covering every single science topic in the curriculum.  Typically, one school year of teaching science will have about 30 science topics to learn, and I have mimicked this with my own videos about each topic.

Thus, a student can use my video to revise a science topic that they have learned at school, or can watch the video prior to their in-class lesson about this topic.

So there are about 30 videos per grade - that makes 180 videos, each about 55 minutes long 🙂

I hope to create a residual income from marketing these videos.  But where to promote them?

My friend Mr Google suggests the Udemy website.  Hmm, that website has a huge range of content, but almost all of the content videos target adults.  My videos are aimed at young students.

YouTube?  Well, I would have to get my videos monetised first, and then I'm not sure that the pay-out would justify the effort.

A major problem is that my popularity as a primary grades science teacher is mostly in China and Russia, not in the USA/EU (this is because of timezone differences).  YouTube is blocked in China unless a VPN is used, and the payment methods on Udemy and other learning websites favour the western world (Google Pay etc).

Perhaps I should 'go it alone'.  I can host my videos on my own website (onlinescienceteacher.com I own the domain but have suspended the website for the moment).  Then I would have to pay for a large amount of web-space to store my hundreds of videos. I do have a suitable payment method (WeChat, Alipay, CC) set up with Stripe.  But I would still have to make potential end-users aware of my products....

Any suggestions?  I think my videos would definitely sell at the correct price (parents pay about $25 for a 'live' online lesson on a topic, so a video sale price of perhaps $10 would be attractive no?)