Useing Keyboard Controls on YouTube App
I am not sure if this has been integrated to YouTube app on iPadOS before, but I found recently that you can rewind, forward, increase and decrease and volume and pause the video using the keyboard attached to the iPad. To perform these functions you can use the familiar controls of arrows and the space bar.
If you are using the desktop website also, you can use the keyboard shortcut keys to control video player controls. I believe it is the same keyboard shortcuts across when using a keyboard and a screen reader or using the keyboard without a screen reader which is really helpful