How can I deactivate the lock screen on Linux Mint 21.2 Cinnamon?

I am just setting up a media center based on Linux Mint 21.2 Cinnamon and have created a user with restricted rights. As the system is to be controlled during operation, it should not go into sleep mode. I have changed the energy settings accordingly. But after a while, the lock screen still appears. I then found this solution on the Internet:

sudo systemctl mask sleep.target suspend.target hibernate.target hybrid-sleep.target

But I was not successful with this either. Can anyone tell me how I can deactivate the switch to the lock screen? I'd appreciate any help. Harry