Function module to determine next empty storage bin

Hello.

I have a program that creates transfer order with multiple items for putaway using FM L_TO_CREATE_MULTIPLE.

The program needs to transfer the stocks to one storage bin per TO, therefore I need to determine the next empty bin for a given storage type before the call to L_TO_CREATE_MULTIPLE. Do you have a suggestion on what function module to use? If there is no function, any table or logic you can recommend to look for the next empty bin for a given storage type?

Thanks in advance.