curl 78 RETR response 550 means a permission denied error. It means that the user is denied to send the same command again as the server will not respond to the same code or command.
This is because the command requires some access to the file that doesn't exist or the user doesn't have proper access permissions.
To resolve this #error >>> https://ibmimedia.com/blog/142/how-to-tackle-curl-78-retr-response-550
#curl : (67) access denied: 530
550 access is denied - filezilla
filezilla error 550
curl: (25) failed ftp upload: 550
550 permission denied
curl: (9) server denied you to change to the given directory
globalscape error code 550