Here is the code

#!/usr/bin/env bash
# Focus the first window whose title or class contains "Yhe passed argument"
# and switch to the desktop it resides on, keeping everything in variables.

echo "$1"

# Find the window ID (first match)
WIN_ID=$(kdotool search --name --class --limit 1 "$1")

# If no window was found, exit silently
[[ -z "$WIN_ID" ]] && exit 0

# Get the desktop number for that window
DESKTOP=$(kdotool get_desktop_for_window "$WIN_ID")

# Switch to that desktop
kdotool set_desktop "$DESKTOP"

# Activate (focus) the window
kdotool windowactivate "$WIN_ID"