Content trust in Docker for Rocky Linux

docker trust inspect --pretty rockylinux/rockylinux:latest
gives
“No signatures or cannot access rockylinux/rockylinux:latest”

docker trust inspect --pretty centos:8
gives

"
SIGNED TAG DIGEST SIGNERS
8 76d24f3ba3317fa945743bb3746fbaf3a0b752f10b10376960de01da70685fbd (Repo Admin)

Administrative keys for centos:8

Repository Key: f4880e657b5b47e2a5eec7d7c5700245e9fde28754c84faada67115c523f7488
Root Key: 95eadfb9877a06161261e4ebed7c8c9f1cbc49ab7f0a5ab246dfcce0d20c3e8c
"

Kindly look into this.