SCP from remote CentOS to Ubunto host

I am having real trouble establishing both SSH and SCP. I need to get some files off my guest machine onto host.

I can ping my host vboxnet0 IP set up in VirtualBox. And vice versa. I have not yet been able to log in. Permission denied.

Not been able to SSH from host, or SCP from VM despite pings and many iterations on ssh and scp etc.

Could someone spell out the sshd_config parameters that will allow me to complete this transfer?

Any help very much welcome.