We can, but you can't, is the basic answer!
Sorry, couldn't resist that.
No, you can't as it stands, but we've been working really hard for the past couple of months on the next major update for PF3, which includes complete support for FS2020 together with a lot of new features and enhancements.
FS2020 support is, of course, reliant on the new FSUIPC7 which, as you may or may not know, is still in Beta and there are still areas of the interface that requiring further work, mostly from MS/Asobo. We also had to await a new version of MakeRwys which I'm pleased to say is with us now and 'should' be out of Beta tomorrow, thanks to Pete/John Dowson and others.
So, whilst we're using PF3 Beta with FS2020 it's not quite ready for release and I'm unable to give any fixed time scales yet, because there's a lot of variables in the mix which are out of my control. But it will be with you just as soon as.