Your friend broke the rules of Fiverr (which are clearly listed on the Terms of Service page). Fiverr blocked your friend’s account as a result. Sellers are required to know and understand the rules here on Fiverr. Usually, when accounts are blocked, they are permanently blocked, and will not be reinstated.
You can certainly have “your friend” contact Fiverr and talk to them about the broken rule, but only Fiverr has the power to do anything with your friend’s blocked account.
We cannot help you with this, because we are not Fiverr Customer Support.