It is really recommended that you just let your account sit dormant instead since this actual CANNOT ever be reversed. If you have gigs, you can pause or delete them and just let the account sit. Eventually Fiverr might delete the account if you are inactive, but many people reconsider after closing a Fiverr account. If you do want to Delete Your Account, though, you can find it under your Proflie > Settings in this area:
You cannot reactivate your account after doing this, though there will probably be cached versions of your gigs and other content on the web for a long time.
“Close my Account”
“Close my Fiverr Account”