EM scheduled backup of LTM failed with error log

Hello All, We are using EM to take rotational backup of all devices and EM scheduled backup failed for only one deivce with a below error message whereas the other devices configured in the EM are working fine.

 

"Message No Permission Suggestions Your current user role does not have administrator permissions on the managed device that you are attempting to manage. Either log on to the Enterprise Manager as administrator or assign administrative privileges to the current user name on the managed device"

 

Could you please guide me on the steps to fix the issue?

 

Could you also help me to know what is the username that EM is using to connect to LTM to run the UCS and get the file?

 

Thanks in advance.

 

Regards, Thiyagu