React Native + typescript => no source

I am trying to get the source code appears in Sentry. I understand it is related to source maps.

I can see the exact place (tsx filename plus correct line number in this tsx - which is some kind of weird? Does that mean that sourcemap is working?) where is the error but not the source code:

The sentry typescript doc mentions to add some code at the really first file (index.js file) but the code is typescript so it does not work as it is an index.js. I also have to add some code in the init but

integrations: [
new RewriteFrames({
root: global.rootdir,

has some typescript error about rootdir no existing.

Is there any working react-native typescript sentry project example anywhere?