Raising temperature by one degree - Climate device

I didn’t do it with the editor, but following this article.

Well the template editor is a debugging tool. It is designed to help with such problems, so give it a try.

After a few attempts I solved it, all I had to do was put the double quotes. For a stupid thing, I wasted a lot of time.

temperature: "{{ state_attr('climate.split_salone' , 'current_temperature') | float | round(0) + 1 }}"

Thanks anyway.