Samsung S9 Booting to TWRP

Hi, I have a Samsung S9 and have been using /e/ for over a year. It is up to date and I used OTA last month. All was good. When I turned on the phone (I don’t think I pressed any key combinations) this morning I was greeted with the TWRP screen: “Mount Decrypt Data - Enter Password”. I selected cancel because I do not know any password. I then got “Unmodified System Partition - Keep System Read Only?” What should I do? I don’t want to break my phone! I am just hoping I can restart the system and go back to how everything was yesterday.

It is quite safe now to “Swipe to modify” (no modification will happen till you ask for it !)

Now you can navigate to Reboot > System.

Great, thank you! That worked.