From Google it looks like PairCare is to do with period tracking. There are already a plethora of apps that do this, a large number of which are free. I'm almost certain it is also a part of the Apple Health stack.
You're an unknown entering into a very large market with a vibe coded SaaS - This isn't going to work.
Usually, this is the beginning of everything, before you write any code. You make this for other people, you need to know what other people need and look for.
Talk to people, make interviews, do analysis of the results, see what's missing...
I searched for your product in Google Play but could not find it. I wanted to have a look and give honest opinion.
So I was thinking "should I make viral app over this?" but still I love my app it helps me a lot and it's my first app so I have big love on it. At the same time, because of above reasons, I was also thinkging I cannot see the situation clearly like maybe it's time to give up.
Just in case if you want to look up this is the website for the app: https://paircare.love/
Three canceled immediately and one got to the paywall and canceled. You have a sample size of 4 users who engaged. That's not "optimize conversion" territory, that's "call them personally and ask what they expected vs what they saw" territory imo. A 15-minute call with each of them will teach you more than any onboarding A/B test from my experience.
If the three who canceled immediately say the same thing ("I thought this was going to do X and it doesn't") — well that's your answer and copy tweaks won't fix it. If they each say something different — the product isn't legibly positioned yet.
At 130 downloads with 2-9/day organic, you don't have a traffic problem. You have a "does this do something specific enough that people want" problem. Fixable, but only by talking to the people who bounced, not by guessing. You must established a channel of communication with your users.
You should ask for feedback constantly.
Improve code quality.
Improve UI/UX.
Write a website for the app, is usually a good landing page.