You better manually validate your OGP machine through steamCMD first by starting an installation with OGP's steamCMD, this way you will have direct console access to input the steam guard and all. If you have double authentication this will be nearly impossible to install from OGP because of the too short period of time you will have to add Steam Guard code to OGP Panel then trigger install again.
If you have basic Steam Guard, you can simply trigger an install, which will fail, then go to Panel settings and type Steam Guard code received in email, then start another install again. so put your steam credentials in OGP Panel Settings. You need to use a steam account with the game licence on it apparently to download the server files.
