I do not think this is possible to do with the repos that Kloxo-MR use. They are limited to php73 for centos 7. To obtain higher versions would require to use for example the remi repo. But that will require software enginering from specialists for the panel to work, and it looks like MR is no longer spending time on this panel. He has spent so much time on Kloxo-MR in the past, but probably received very little donations and lost interrest.