Problems with users and groups of shared directories created in OceanStor9000

I created a shared directory named atm in OceanStor9000. The user and group of the directory are root. The permission is 777. It is shared to a server 192.168.0.12 using the NFS protocol, the quota is limited to 1500G, and the stripe is 128k. . I created a directory called /home/atm/datafile on the server of 192.168.0.12 as the application user atm. The users and groups of this directory are both atm. After I mount it like this

mount -t nfs xxx.xxx.xxx.xxx:/atm/ /home/atm/datafile

Then enter /home/atm/datafile as an atm user, the users and groups of all files created have become nobody instead of the expected atm.

In this case, I tried to change the user and group of the directory from root to atm when creating the atm shared directory, but found that it couldn’t do this. What should I do to solve this problem?

Thanks