I thought I did answer the how question -

I airdrop the video from the phone to my laptop. Import it into iMovie, add a thumbnail I do in canva and upload it to YouTube. Then, I download it from Youtube to a mp4 file - upload it to DTube, add text and the same thumbnail I made for the video and we are in business.

If you want to know how I learned about it - by seeing other freewriters publish Dtube snaps and giving the same disclaimer in their posts as I do - @nathanmars got the initiative started to get more people to use and engage on Dtube.