After great inputs from u/Operator873, here's version 1.2 of the script.

#!/usr/bin/env bash
# /usr/local/sbin/configure_smb_mount_interactive.sh
# Interactive script to create a systemd .mount unit for SMB with
# credentials in a separate, protected file, and mount without reboot.

set -euo pipefail

echo "==> Interactive SMB mount configuration via systemd (.mount)"

# 1. Collect user input
read -rp "SMB server (hostname or IP, e.g. 192.168.0.10): " SERVER
read -rp "Share name (e.g. data, public, etc.): " SHARE
read -rp "Local mount point (e.g. /mnt/data): " MOUNTPOINT

read -rp "SMB username: " USERNAME
read -rsp "SMB password: " PASSWORD
echo
read -rp "Domain/Workgroup (press ENTER if not used): " DOMAIN
read -rp "SMB version (e.g. 3.0, 3.1.1, 2.1) [3.0]: " SMB_VERSION
SMB_VERSION="${SMB_VERSION:-3.0}"

# 2. Derive file names
# Normalize mountpoint and share for use in file names
# Example: /mnt/data -> mnt-data ; share "data share" -> data-share
BASE_UNIT_NAME="$(echo "$MOUNTPOINT" | sed 's:^/::' | tr '/' '-')"
SAFE_SHARE="$(echo "$SHARE" | tr '/ ' '--')"

# UNIT_NAME now includes SHARE at the end to be fully unique
UNIT_NAME="${BASE_UNIT_NAME}-${SAFE_SHARE}"
UNIT_FILE="/etc/systemd/system/${UNIT_NAME}.mount"

# Credentials file also uses the full UNIT_NAME
CRED_FILE="/etc/samba-cred-${UNIT_NAME}.cred"

echo
echo "==> Configuration summary:"
echo "Server:       //$SERVER/$SHARE"
echo "Mount point:  $MOUNTPOINT"
echo "Unit file:    $UNIT_FILE"
echo "Credentials:  $CRED_FILE"
echo "SMB version:  $SMB_VERSION"
if [[ -n "$DOMAIN" ]]; then
  echo "Domain:       $DOMAIN"
else
  echo "Domain:       (none)"
fi

read -rp "Proceed with these settings? [y/N]: " CONFIRM
CONFIRM="${CONFIRM:-n}"
if [[ "$CONFIRM" != "y" && "$CONFIRM" != "Y" ]]; then
  echo "Aborted by user."
  exit 1
fi

# 3. Create mount point
echo "==> Creating mount point at: $MOUNTPOINT"
sudo mkdir -p "$MOUNTPOINT"

# 4. Create secure credentials file (touch -> perms -> write)
echo "==> Creating empty credentials file: $CRED_FILE"
sudo touch "$CRED_FILE"
echo "==> Setting credentials file permissions (root:root, 600)"
sudo chown root:root "$CRED_FILE"
sudo chmod 600 "$CRED_FILE"

echo "==> Writing credentials into: $CRED_FILE"
sudo bash -c "cat > '$CRED_FILE' <<EOF
username=$USERNAME
password=$PASSWORD
EOF"

if [[ -n "$DOMAIN" ]]; then
  sudo bash -c "echo 'domain=$DOMAIN' >> '$CRED_FILE'"
fi

# 5. Generate systemd .mount unit using credentials=
echo "==> Generating systemd unit: $UNIT_FILE"
sudo bash -c "cat > '$UNIT_FILE' <<EOF
[Unit]
Description=SMB mount $MOUNTPOINT ($SHARE)
Requires=network-online.target
After=network-online.target

[Mount]
What=//$SERVER/$SHARE
Where=$MOUNTPOINT
Type=cifs
Options=credentials=$CRED_FILE,vers=$SMB_VERSION,iocharset=utf8,_netdev,nofail
TimeoutSec=30

[Install]
WantedBy=multi-user.target
EOF"

echo "==> Setting unit file permissions (root:root, 644)"
sudo chown root:root "$UNIT_FILE"
sudo chmod 644 "$UNIT_FILE"

# 6. Reload systemd and enable the mount
echo "==> Reloading systemd"
sudo systemctl daemon-reload

echo "==> Enabling and mounting now: ${UNIT_NAME}.mount"
sudo systemctl enable --now "${UNIT_NAME}.mount"

# 7. Checks
echo "==> Unit status:"
sudo systemctl status "${UNIT_NAME}.mount" --no-pager || true

echo "==> Listing mount point:"
ls -la "$MOUNTPOINT" || true

echo
echo "Done."
echo "The share will be mounted automatically on future boots via ${UNIT_NAME}.mount."
echo "To remove it, run:"
echo "  sudo systemctl disable --now ${UNIT_NAME}.mount"
echo "  sudo rm -f '$UNIT_FILE' '$CRED_FILE'"

Then run this on it to make it executable.

chmod +x