I attach a patch for adding a preference setting to control automatic copying to clipboard of the code. The patch is Android only -- Sorry I have no knowledge or access to iOS development. 

Basically adds a standard android settings activity with a single preference, and does not copy to clipboard if not set. The default is to copy, which is in-line with current behavior.

I attach the git patch, let me know if the format it OK

Thanks for FreeOTP,