gtm_add failure

f5 GTM 1600 running on 11.2 version , we are getting below error while perform gtm_add command . kindly advise

[xyz:Active:Standalone] ~ gtm_add John@165.222.138.245 WARNING: Running this script will wipe out the current configuration files (bigip_gtm.conf, named.conf and named zone files) on the BIG-IP GTM Controller on which this script is run. The configuration will be replaced with the configuration of the remote BIG-IP GTM Controller in the specified sync group The local BIG-IP GTM MUST already be added in the configuration of the other GTM.

Are you absolutely sure you want to do this? [y/n] y

==> Running 'bigstart shutdown gtmd' on the local system ==> Running 'bigstart shutdown zrd' on the local system ==> Running 'bigstart shutdown named' on the local system Retrieving remote and installing local BIG-IP's SSL certs ... Enter john password if prompted Password: Syntax Error: "-f" unexpected argument ERROR: Can't read remote cert via /usr/bin/ssh.

Restarting gtmd Restarting named[43511425@cgbf-bh26-3002:gtmd DOWN:Standalone] ~