Install Magisk AND keep TWRP

I have happily used Magisk and TWRP for about a year but today I wanted to update the /e/ OS to 1.1. But that went wrong. After downloading the OTA, the updater proceeded to install the update, but on the way the updater app crashed. There was no way to complete the installation. I tried a reboot and after that the update was unexpectedly completed and Magisk and TWRP were gone. The phone is now on /e/ 1.1-20220705201319. I’ve tried to get Magisk back and TWRP, but: every time I installed Magisk out of TWRP, TWRP was gone. And every time I installed TWRP, Magisk was gone afterward. Does anybody know a proven method to install BOTH Magisk and TWRP on the FP3?