No, we are not a registrar ;)
That said, you can set up a redirect, alias or cname at your registrar, also there are dedicated redirect service providers. Long story short: custom domains are well possible, setup is however on the other side.
Hope that helps!
@codeberg @IzzyOnDroid @storchp @mondstern @firstname.lastname@example.org Sorry to bother again. But I think in order for this to work, pages must get a codeberg.org subdomain (not path), see https://codeberg.org/Codeberg/Community/issues/115