It depends on how your friend has set things up.
If he has simply created a machine user for your domain, then you will only have FTP and/or SSH access.
However, your friend can create a new WEBID (panel log-in) and give this WEBID certain panel privileges for your domain. This is done by going to Billing -> Account Privileges in the panel.
If you really want/need panel access, you could ask your friend to create such a WEBID for you. Of-course, the other option is to purchase a hosting plan for yourself.
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