I see Liberty Lite isn't working for many of you as it hasn't worked for me.
Follow these steps for an alternative way to bypass jailbreak detection!
1. Uninstall Mario Kart Tour
2. Disable any other jailbreak detection tweaks from MKT (you don't have to uninstall them)
3. Install Shadow (Repo: https://ios.jjolano.me/)
4. Re-Install MKT but don't open the app
5. Open Shadow settings
6. Make sure 'Bypass Detection Libraries' is enabled. This should be enabled by default.
7. Add Mario Kart Tour to the Applications list under Application Settings.
8. Scroll down and add MKT to 'Filter Dynamic Linker' under Dynamic Linker.
The app should work now. After the first race it you might be stuck on the finished race loop. Just wait a few minutes and it should take you to the next screen. Make sure you phone doesn't lock.
Let me know down below if this worked for you or you need any further assistance!