I am also getting this error when trying a cache rebuild:
D:\Bitnami\MyDrupalSite>php "D:\Bitnami\MyDrupalSite\apps\drupal\drush\drush" cr
Command cache-rebuild needs a higher bootstrap level to run - you will need to invoke drush from a more [error]
functional Drupal environment to run this command.
Command cache-rebuild requires Drupal core version 8+ to run. [error]
The drush command 'cr' could not be executed.
Makes no sense at all since I am using drupal 8 and a higher bootstrap level to run? Something is obviously not right. The bitnami version I installed is "Drupal 8.9.7-0"