Hello @Maximilian-Gerhardt , thanks for your response! I did the command dmesg, and I read the whole log, and I didn't have

uvcvideo: Found UVC 1.00 device USB 2.0 PC Cam (5149: 13d3) input: USB 2.0 PC Cam as /devices/platform/101c0000.ehci/usb1/1-1/1-1:1.0/input/input0

like @CAP-33 (or something similar). So I assume that my webcam is not detected by the system, it was probably the problem! So I will take another. Thank you again