To be absolutely certain:
1. Consult your owner's manual: This is the best source of information for your specific vehicle. It will show you exactly where the dipstick is (if there is one) and how to check and add fluid.
2. Look around the passenger side of the engine bay: Carefully inspect the area near the firewall. The dipstick may be reddish-orange or dark brown in color.
If you can't locate a dipstick, do not attempt to add transmission fluid yourself. A sealed transmission system requires specialized equipment and knowledge to avoid damage. Take your vehicle to a qualified mechanic for transmission fluid checks and services.