If I m right some user just use the cat command to create a file, perhaps this command is native on docker ?
cat >file.json
An other user, put the file on an external device and use
docker cp /mnt/data/supervisor/share/lixee_zlinky_historique_mono.json 26abed96b08c:/data/.local/share/dresden-elektronik/deCONZ/devices
To copy the file ( 26abed96b08c is the ID)
Another method to test (don’t forget the ')
touch file.json
printf 'file_contain'