The TLS cert has to be uploaded to iDRAC via racadm:
#!/bin/bash server=$1 racadm -r $server -u root -p <password> sslkeyupload -t 1 -f <privatekeyfile>.key racadm -r $server -u root -p <password> sslcertupload -t 1 -f <certificatefile>.crt racadm -r $server -u root -p <password> racreset