Here are the download links for every PSPi image.
Current versions are available on Proton Drive and by Torrent. Old versions are available by Torrent.

PSPi Zero Version 5 Images

Current:
February 3, 2022 image for Raspberry Pi Zero and Raspberry Pi Zero W – Proton Drive or Torrent
February 4, 2022 image for Raspberry Pi Zero 2 W – Proton Drive or Torrent

Outdated:
August 17, 2021 image for the Raspberry Pi Zero and Raspberry Pi Zero W – Torrent
November 8, 2021 image for the Raspberry Pi Zero 2 W – Torrent

PSPi Version 4 Images

Current:
November 18, 2021 image for the Raspberry Pi Zero and Raspberry Pi Zero W – Proton Drive or Torrent
November 19, 2021 image for the Raspberry Pi Zero 2 W – Proton Drive or Torrent

Outdated:
March 24, 2018 image for the Raspberry Pi Zero and Raspberry Pi Zero W – Torrent