You can legally tow a car with another car using a tow chain, tow rope as long as you don't drive very far with it and keep the flashers on the towing car going.
If the flashers are not working on the car being towed then you should use some towing lights that are magnetic that attach to the cars body and then use them to flash to show other vehicles that you're going slower.
If you need to tow the car or vehicle further than 20 miles then you need to put the car on a car tow dolly or on a car trailer or have a towing place tow the vehicle for you.
But short distance tows with a tow chain or rope are usually mostly legal in most states as long as you safely tow the vehicle.
I've towed a few vehicles for people myself with a tow chain and have never been stopped by the police for it.