Rockpi 3A Android Rooting problem

I fused rk356x_rock_3a_box_20220721.1535_gpt.img and run.
Next Enter Fastboot → Enter recovery
However it does not go to TWRP recovery mode. Just goes to main recovery mode.
Would you please advise me how to go to TWRP recovery mode?
Also please guide how to rooting Android11 Rock 3A.

Did you install TWRP?