bash 5.2.x + ternary operator: How can I use this combo when checking if my string variable is empty or not?

I have tried #!/bin/bash distro="" myvar1=[[ -n "$distro" ]] && echo $distro || echo "debian" myvar2=$((-n $distro ? $distro : "debian")) these are the results of the script ./build.sh: line 5: -n: command not found debian ./build.sh: line 6: -n ? : debian: expression expected (error token is ": debian")