leaking transmission fluid
Since the car is 20 years old I’m not surprised. How bad is the leak? How frequently do you need to add fluid? How many miles are on your Corolla and what condition is it in otherwise? If you’re lucky it’s something simple like a bad pan gasket. If not, I have no experience with stop-leak products but I wouldn’t put much money into the car. Have a mechanic you trust look at it and get a quote. If it can’t be fixed inexpensively and it’s not a bad leak, I’d live with it until you can’t any more.
Edited because I apparently can’t add.
How do you know it is leaking? What is the level on the dip stick?
A few drops under the car once in a while is not an emergency, call your mechanic and make an appointment.
If your feet are getting wet because there is a puddle of fluid you have big time problems.
Do not drive the car if the level is low, have it towed to a mechanic. Driving a car with low trans fluid is a sure fire way to burn the transmission beyond repair.