Use a List, add the images path in the list and then put the list variable in OpenFileResult, if you use a string array instead of list it will not work.
@GaG
Thanks again for your help, but I finally solve the problem using a loop and a list.
Just by mistake, I found this thread: https://community.bablosoft.com/topic/11372/bulk-image-upload
And it helped!
I was searching for few days and found this only now lol.