WSL cannot open vscode using "code ."

When I tried to open vscode in WSL Ubuntu 20.04 using command code .,it failed and the following message was logged:

/mnt/c/Users/john/.vscode/extensions/ms-vscode-remote.remote-wsl-0.50.1/scripts/wslCode.sh: 57: /home/john/.vscode-server/bin/d2e414d9e4239a252d1ab117bd7067f125afd80a/bin/code: not found

I would like to ask how to fix this problem? Thx a lot!