send reply to email missing thread in replay

[sebaKwiat]

I am trying to implement replay for google email with original email beying replays threads with responded. I just do not know how to do it it responds however without threading original email. I have raise stack overflow ticket for it perhaps someone here could help?

https://stackoverflow.com/questions/69351272/send-reply-to-email-by-gmail-api-missing-thread-in-replay.

I also see that there is missing such example in the project repo. If i try to convert example from project repo i get the same results.