Solved. I found a boot-repair tool. Run it from live CD and it repaired my ubuntu installation. Thanks for answers and help!

Thank you all very much for your replies and help. Removing the disk and battery helped, the laptop turned on to UEFI settings. But does anyone have an idea how to solve this bootloop with Ubuntu now? Fresh system and partitioning through the default settings of the ubuntu 25.04 installer. When I turn it on this message appears for a few seconds and then the computer resets. One tutorial on the internet told me to turn on secure boot but as you can see from my first post it didn't do anything.

Removing SSD and battery help. Thank you.

I can but it doesn't help. When I turn it back on, the same message appears and I still can't do anything.

This the photo from the back cover.

I tried it and it doesn't work. Also I tried to reset by emergency reset hole and it also doesn't work

I can't get into BIOS setting, it's stuck on the message from my first post.

Photo moments before the tragedy. I changed these settings.