Normally I'd say do this;

The place you want to copy the log backups to; right-click on the folder > Properties > Security and see if the Service Account has permissions there. If not, grant it permissions.

HOWEVER it looks as though you are using an account that is local to your machine so that won't work; you need to use an account with domain privileges for this or you won't be able to set up log-shipping to another machine or server.

Do you have a Windows sysadmin there who can help you?