panelizing boards

[Boschi]

i have some small boards that i would like to panelize into a single PCB.

so far i have found https://hackaday.com/2017/06/21/panelizing-boards-the-easy-way/ this, but it crashes pretty frequently and i dont get how it should work.
(pro tip! it accepts directly a folder with the files in it, not a zip. or i have misunderstood how it work)

has anyone used this program or something else that gets the job done?
im trying to do so because for 2oz board they charge you by the panel, not by board size

thanks for your help!