I am just using AME and I am new, why AME doesn't support Dolby/DTS codecs?
Since CC 2017, Adobe now no longer supports export/encoding to Dolby Digital. Although the patents for AC-3 expired in 2017, the expiration applies only to decoding (playback). Encoding AC-3 still requires license payments to Dolby Laboratories, which also now requires a very-high-priced perpetual license or one-time-purchase software. This is why Dolby support has been completely removed from all Adobe software beginning in 2017, while Dolby decoding support has been moved to the OS (Windows, macOS) natively.
Adobe never supported DTS at all.
So why I can't select DTS when I choose BD for encoding?
Edit: Why I can't edit my posts! I mean explain why Adobe doesn't support DTS? again license issues?
Yes. License issues.
The name of this program is Adobe Media Encoder, but the real name is: Adobe Ain't Media Encoder.