Currently debug-leetcode only support Python3, Javascript and cpp language and in the future we will support more lanuages which support vscode debug protocal. Welcome to get PR for another language. My next plan is to support c and java.
Not all problems are supported(most free problems are supported) and only supported problems have debug option.
If you have any issue about the debug feature, you can create a issue with detail information
Step 2. Install a supported version of Python3 on your system (note: that the system install of Python on macOS is not supported) and add python command to your environment.