Invalid zip file format - Magisk 22.1

You have downloaded the "Source code" release of Magisk which is for developers you want to build/compile Magisk on their own or make modifications to the code.

If you want to install Magisk from within a custom recovery ROM such as TWRP since Magisk v22.0 you have download the "APK" release which is at the same time a ZIP file with can be installed via recovery:

In some custom recoveries, the installation may fail silently (it
might look like success but in reality it bootloops). This is because
the installer scripts cannot properly detect the correct device info
or the recovery environment does not meet its expectation. If you face
any issues, use the Patch Image method as it is guaranteed to work
100% of the time. Due to this reason, installing Magisk through custom
recoveries on modern devices is no longer recommended. The custom
recovery installation method exists purely for legacy support.

• Download the Magisk APK


• Rename the .apk file extension to .zip, for
  example: Magisk-v22.0.apk → Magisk-v22.0.zip. If you have trouble
  renaming the file extension (like on Windows), use a file manager on
  Android or the one included in TWRP to rename the file.


• Flash the zip
  just like any other ordinary flashable zip.


• Warning: sepolicy.rule
  file of modules may be stored in cache partition, do not clear it.


• Check whether the Magisk app is installed. If it isn’t installed
  automatically, manually install the APK.

https://topjohnwu.github.io/Magisk/install.html#custom-recovery