Support and the freedom to move matter more than an ideal meditation pose.
Start with support
Use a chair, cushion or resting surface that supports you comfortably. Rest the hands where they do not need to hold the body upright. You can keep both feet supported if that works for your position.
Adjust early and often
Change position when something feels uncomfortable. Movement does not invalidate a practice. If scanning a particular body area feels unpleasant, skip it and notice the room or a neutral contact point instead.
For a resting lesson
Extinguish flames before lying down or closing your eyes. Put the screen where you do not need to hold it. Choose a voice volume you can hear without strain, and leave background sound off if it competes with the guidance.
Try a short comparison
Notice your hand touching a surface, then your feet on their support. Which is easier to feel without effort? Choose that point as your anchor for a few moments.
General wellbeing guidance from Mahonie. Adapt or stop any practice when you prefer.