It seems that Avid is offering for this month only Pro Tools reinstatements for those with expired perpetual licenses--$249 for regular Pro Tools and and $499 for Ultimate. You can get it from Avid here:
https://www.avid.com/special-offers/...nt-2021-pt-sib. But it looks like third party sellers have them as well; for example:
https://www.rspeaudio.com/Pro-Tools-...nts-s/2569.htm.