Well, your comic looks gorgeous, so it's definitely not a quality issue.
Tapas is not great for organic growth through the site itself. Nobody actually looks at the 'fresh' section. You have to promote, and promote heavily, offsite. You can start here on the forums. Reddit is also a very useful place to promote your comic, with various subreddits suitable for that. Running Instagram and Twitter accounts for your comic, where you post panels, sketches, and so-on are also very helpful for getting eyes on your work.
Also, regardless of what you think of the app itself and the people who own it, TikTok is one of the better platforms to get new eyes on your work.
Also, there's absolutely no reason you should only post on Tapas. WEBTOON has a way bigger audience. You'll need to slice your pages and re-arrange them vertically to see success over there, but you have nice big white gutters, so that should be an easy task.