How to check keywords for your application if it is not in the market yet?

Question

Apple App Store

Hello!
We'll be launching our first app on the App Store soon, but we don't know which service will be the best for keyword optimization. Sensor Tower, MobiledevHQ, etc. help only if our application is already on the market.
And what service will help us optimize keywords in advance?
Thanks for answers!

Answer 1

Movement No. 1
A perm semantic core is assembled in wordstat.yandex.ru and https://adwords.google.com/KeywordPlanner .
Movement No. 2
HF and MF are taken for work .
Movement No. 3.
Put it in stores and monitor the Sensor Tower, etc. Enter a correction.
Movement #4
Going to Movement #1 in 1-2 months