When should the GRE scores be submitted by?

Hello,

I'm a bit confused about the deadline to submit GRE scores for PT schools.
I understand that they may differ, but

1. Is it usually by the PTCAS application deadline? Meaning, should it already have been submitted by the time I press "submit application" button on the PTCAS?

2. I know sending GRE scores takes a few weeks, so I'm wondering if I need to take the GRE a few weeks in advance, or just take it after I submit my PTCAS and send the scores in.

Thank you!