Using MAVSDK ftp GRPC for downloading logs


I am trying to download log files stored in the px4, from a mobile device that communicates with a Mavsdk server that runs on Raspberry-pi, which is connected with a cable to the px4. The mobile application uses GRPC service methods that are implemented in the Mavsdk server. The download of log files does not work for me (when called from the mobile device). It looks like that the log file download assumes that the log file is about to be copied to the computer in which the Mavsdk server runs.
My questions are:
(1) Is my assumption true, that the log download can be performed only to the Raspberry-pi, in my case.
(2) Is there a way to perform the wanted download without storing the log on the Raspberry-pi? For instance by using the ftp services included in the Mavsdk API.