Enable NFS service in the Qnap NAS settings:
Assuming you are using Debian.
Install NFS support:
sudo apt install nfs-common
Create a mount point:
sudo mkdir -p /mnt/qnap
Mount the NFS share:
sudo mount -t nfs qnap.local:Share /mnt/qnap
To make the mount permanent edit /etc/fstab:
qnap.local:Share /mnt/qnap nfs defaults 0 0
If the above does not work and the share is not mounted at boot, you can try the following:
qnap.local:Share /mnt/qnap nfs nofail,x-systemd.automount,x-systemd.requires=network-online.target,x-systemd.device-timeout=10s 0 0