Where Mender download the artifact payload

Hi,
I’m trying to create my own update module which will download some sort of binary Python file and build them into a Docker container.

I would like to add all my binary into the artifact payload. My idea was to group them into a .tar file, add it on the artifact payload and then download them into my Raspberry Pi 4, decompress from the .tar file and build it.

Now, from what I’ve understood from the documentation to add file to the payload of an artifact I’ve to use the -f flag

When the artifact is uploaded to Mender and then the update has been launched on the Raspberry, where will the payload be downloaded during the download phase? I need to know the location so I’m able to run the docker build command to create the updated image