write to hd connected to raspberry pi 3b +

Good evening,
I write to you because I have a problem that I can’t solve,
I have a raspberry 3Pi b + on which I have installed volume for the management of my liquid music that I connected via usb to the rasberry.
I use a Mac computer, on shared computers, I see the USB connected I can access the folder with flac files, however I can’t import anything because I believe it has limitations regarding the authorizations.
could you help me
the disk is formatted in os x extended journaled

This is a very important remark, and you are in the right direction here.

Volumio is Linux-based (Raspbian, a Debian-derivative for Raspberry Pi’s). It does not play well out-of-the-box with the default Mac OS’ HFS+ drive formatting.
Now you have two options to get it to work:

  1. Format your drive into a Raspbian-friendly format like Ext4. This will also massively benefit performance of the drive, resulting in a smoother experience.
  2. Install hfsplus drivers (see below). This option is least preferred since your Volumio installation is now custom and might not work well with updates etc. anymore.
    Note:never do apt-get update and upgrade on Volumio! It is almost sure to break the installation.

sudo apt-get install hfsplus hfsutils hfsprogs (from: raspberrypi.stackexchange.com/q … windows-pc)

thanks for your answer

I think that I format the disk in ext4, because it seems to have understood that by installing the hfsplus drivers I can only read but not write to the shared usb disk.