If you don't already have a code for DP5, I'm afraid it is too late to get that one now. But you can get one for DP7.
Direct downloads are not available for the full installers because they are tied to your apple id you use to redeem the code.
Direct downloads for all the delta updates DP2-DP7 are however available in apple's developer forums because they are not tied to ids.
So you could get them to update from DP1, DP2, DP3, DP4, DP5 if you want to (and then go even further to DP6 and DP7 if you want to).
But for a clean install of DP7 it would be better to just redeem a code for DP7, make a bootable USB installer using instructions in this thread:
https://forums.macrumors.com/threads/1761645/ , boot up with the option key, erase the drive and install from there.