I'm sorry but looking back at my post I see that I didn't explain my situation very well. Actually I did buy an OTG cable from eBay as you describe. I plugged a SanDisk USB flash drive into the standard end of the OTG cable and then plugged the micro-USB end of the OTG cable into the charging port of my Samsung Galaxy S4 Active.(Now I am going to ad the rest of my original post.) But when I plug the end of the cable into the charging port, I don't get a notification that shows the phone recognizing it. I get no message at all. And it is not listed as being there when I look in My Files. I've looked at YouTube how-to videos on how to set it up, but I haven't seen any that show any setting that I'm supposed to do? Is there a setting for this, or is the phone supposed to recognize it on it's own, or what should I do?
I have done further research since I made this post, and the question is now more complicated. I have discovered that Samsung doesn't actually support an OTG for the S4 Active (Model SGH-I537), even though it does fit physically. I have found that my phone was built when the USB technology was prior to the USB 2.0 and that it actually is compatible with an OTG on-the-go 1.3. It seems that the OTG cables available are all version 2.0. I am curently trying to locate the 1.3 cable, but I have a feeling I won't find one. So this is my new dilemna. Thanks for your reply, however.