The instructions only have 4.2 for some reason (@dscryber) which lists it as: https://packages.graylog2.org/repo/packages/graylog-4.2-repository_latest.rpmsudo
with rpmsudo on the end rather than rpm I don’t know if that would fix it but maybe if you change that line to 4.3 it may fix it … EDIT… needs to be a space before the sudo… I need to pay more attention to the copy/paste… error is in docs though!