how can i copy media files( movie, picture, audio, data files....) from samsung note 10+(android) to openmediavault 5(debian) NAS storage(exfat) using USB port of Raspberry Pi4 ?

Are you running OMV?

Create a shared folder, create a share (NFS or SAMBA).

Find a smb or nfs client for android

copy.

What is "media"?

Is "media" in multiple directories? ie. internal storage and SD card.

Will the transfers be exclusively 1 way, phone to NAS?

Here's a question, by default does OMV auto mount or use MTP, PTP, etc. or do you need to install mtp-tools (or whatever)?

For music on a old phone I used to have a script poll for 2 different directories for copy/sync. While you won't be able to see/select, this is very simple if all you want to do is copy/overwrite newer/different files. However, getting it to (auto)mount so I could use /a/sane/path in the script did require a fuse derivative to mount the disks. If I remember correctly, it's MTP that does not share a typical filesystem with the host.

I use on my mobile phone the Total Commander and the LAN-Plugin.

On OMV I create a Samba-Share connect them via WLAN and copy.