Cant share a folder

That won’t work because the path doesn’t exist until you mount it.

You need to mount it ot a permanent location e.g. /data/smb/share - then create a bind mount from /data/smb/share to /srv/smb/share and add /srv/smb/share to your smb.conf.

Also set your smb version as high as possible

[global]
   min protocol = SMB2
   max protocol = SMB3

Doing it as described achives two goals

  1. Secure you server’s filesystem from accidental file system access outside the share
  2. Secure the share against from being discovered by ransomware using netbios to locate windows shares.