There is no entry in /etc/fstab because it is an automounted filesystem. If I run cat /etc/mtab I see these two entries:
/etc/auto.misc /home/luno/nfs autofs rw,relatime,fd=6,pgrp=242858,timeout=20,minproto=5,maxproto=5,indirect,pipe_ino=1619553 0 0
192.168.4.7:/nfsexport/franzi /home/luno/nfs/franzi nfs4 rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,soft,fatal_neterrors=none,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.4.9,local_lock=none,addr=192.168.4.7 0 0
In /proc/mounts I see:
/etc/auto.misc /home/luno/nfs autofs rw,relatime,fd=6,pgrp=242858,timeout=20,minproto=5,maxproto=5,indirect,pipe_ino=1619553 0 0
192.168.4.7:/nfsexport/franzi /home/luno/nfs/franzi nfs4 rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,soft,fatal_neterrors=none,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.4.9,local_lock=none,addr=192.168.4.7 0 0