How to configure H264 encoder with AVCC, instead of AnnexB ?

Excuse me, I have a question while using NVENC to encode video to H264.

I never find any param to set AVCC or AnnexB. By parsing NALU, I can know NVENC is using AnnexB.

I want to know>
How to configure H264 encoder with AVCC, instead of AnnexB ?
By the way, the SDK I am using is version-9.0.

Thank you !