leaked all of the transmission fluid out

The tranny fluid goes to the radiator to cool down. Usually there are two lines send and return., On the radiator, the lines are each set in a special connector on the right (passenger) side of the radiator. If one of the connectors fails, the fluid under pressure will leak out.
In your case, since the rate of loss is faster, your lines may be really loose.

The lines are clearly visible, but are harder to get to. Specially the bottom one.
The nut there is a internal flaring nut. You will need a special too to release it.

Then you unscrew the connector from the radiator, insert the new connector and reseat the line. Please make sure that you look up this procedure in the manual to see the lines and location of the parts.

Refilling your transmission is tricky, follow the manual on how to add fluid if needed.

Yes. This is most likely a cooler or a line issue so we need to locate the exact location of the leak by laying on the ground and seeing where it is dripping from.

I am attaching the process from the manual on how to replace this cooler but it also shows the lines that we need to inspect.

Please run through this material and see what turns up. Please let us know if something else is leaking and we can go from there. Thanks