The PGWP public policy has ended and hasn't been extended. So as of now, no, you unfortunately cannot apply to extend your PGWP.
My personal opinion is that it's unlikely IRCC will reopen this public policy. If they were going to do this, I think they would have done this last year and extended the program rather than closing it. That's just my opinion.
I would personally recommend that you start thinking what your backup plan will be. Definitely do not count on the public policy reopening.
If you want to remain in Canada, you can certainly apply to change your status to visitor. However this unfortunately will not allow you to keep working.
If you want to remain and work, you need a job offer and approved LMIA so that you can apply for a closed work permit.
Good luck.