Sorry @minajo, I forgot to add links with some information on the practice of yoga nidra.
https://www.dailyom.com/journal/your-brain-on-yoga-nidra-and-why-you-need-this-powerful-yoga-practice-in-your-life/?aff=910&ad=1&utm_source=google&utm_medium=ppc&utm_campaign=PerformanceMaxMeditation&acct=9358138875&gad_source=1&gclid=CjwKCAiA2pyuBhBKEiwApLaIOyABin15IjK4aMrSsiwk5K9OCJzm5pbXhjP_1dswlqWGO0exCZgOthoCp6EQAvD_BwE
https://www.biharyoga.net/yoga-nidra.php
Chris (Santosha)