Something worth trying is to find a featured webtoon in a similar genre as yours and upload around when it uploads. I write a drama/romance and had people commenting they just came from I Love Yoo to read mine. Since the big featured comics notify them, they'll be using the app and might have chance of finding your comic this way.
I haven't purposefully put that theory to the test, just something I thought I'd throw out there to try.
If you happen to know where the majority of your readerbase is from, try uploading with their timezone in mind ^^