'Pages' is the wrong way to think about Webtoon. If you're hoping to be successful there, you want to think in 'episodes'.
- How many panels does it take you to convey a story beat?
- How long does that take you to draw?
- Is it possible to split that story beat into smaller yet still satisfying segments?
Those should be the determining factors for how often you upload on Webtoon.
My episodes are typically between 18 to 28 panels, depending on much complexity I need to tell a small chunk of my story. I uploaded once every 2 weeks in 2021, and it will be once every 3 weeks for a while this year, as I keep having other comic industry work heaped on me.
Another thing with Webtoon which is important to keep in mind is that the overwhelming majority of readers read on their phones. As such, the page format is deeply unpopular there. You may still find some readers - but if you want to be successful on Webtoon, you must reformat your episodes to the vertical scrolling format. Take it from someone who tried page format, and only started seeing success after reformatting for scroll.