No graphical display with an Nvidia card

OK.

I don’t know how to add the other parameters you wrote.
I know that i can edit the file before I start linux. Just seems to be a little bit complicated because there is much code for every kernel. My idea is to edit only 5.10 because I’m using this usually…

Is this the right way to edit/add the parameters?

I did it now this way: I add your written parameters at this position: GRUB_CMDLINE_LINUX_DEFAULT=“…your writen parameters” after the other parameter that i enabled again.
I did this again:

sudo update-grub

and did a reboot.
I don’t see a difference. But i see know text messages while booting.