I lost my save and I wanted to know if there is a way to unlock levels or chapters with cheats? I finished third chapter.

Try put this on console:
/spdevmap

Try put this on console:
/spdevmap
This will unlock levels?
Thanks, I'll try later.

Try put this on console:
/spdevmap
This will unlock levels?
Thanks, I'll try later.
This will probably allow you to load the first map of fourth сhapter.

This will unlock levels?
Thanks, I'll try later.
This will probably allow you to load the first map of fourth сhapter.
Great, thank you!
Where do I write it, in the menu?

This will probably allow you to load the first map of fourth сhapter.
Great, thank you!
Where do I write it, in the menu?
SHIFT+ESC and then type command above.

Thanks for the help!