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