running script gives jq: error (at <stdin>:0): Cannot iterate over null (null)

/srv/chat$ sudo docker compose exec synatainer purge_rooms_no_local_members.sh
jq: error (at <stdin>:0): Cannot iterate over null (null)

/srv/chat$ sudo docker compose exec synatainer stui info
Synatainer/stui configuration info.
stui version: v0.4.2
Running inside container (docker). Nice.
Environment varables:
CONFIG_FILE not set
BEARER_TOKEN not set
SYNAPSE_HOST not set
MXPASSFILE not set
DB_HOST not set
DB_NAME not set
DB_USER not set
PGPASSWORD not set
PGPASSFILE not set
VACUUM_DB not set
STATE_AUTOCOMPRESSOR_CHUNK_SIZE not set
STATE_AUTOCOMPRESSOR_CHUNKS_TO_COMPRESS not set
STATE_AUTOCOMPRESSOR_CHUNK_SIZE_BIG not set
STATE_AUTOCOMPRESSOR_CHUNKS_TO_COMPRESS_BIG not set
MEDIA_MAX_AGE not set
ROOM_KEEP_LIST not set
HISTORY_MAX_AGE not set
HISTORY_ROOM_LIST not set
HISTORY_KEEP_LIST not set

Default Configuration Files:
Testing file '/conf/synatainer.conf' .. exists and seems readable. Nice :)
Testing file '/conf/pgpassword' .. exists and seems readable. Nice :)
Testing file '/conf/mxtoken' .. does not exist.
Testing file '/conf/keep_rooms.list' .. does not exist.
Testing file '/conf/purge_history.list' .. does not exist.
Testing file '/conf/keep_history.list' .. does not exist.
Done.

Can't tell much more…