用npm i -g typescript安装报错：EEXIST: file already exists，
用npm view typescript version查看版本显示4.8.4
但是用tsc命令的时候又报：This is not the tsc command you are looking for错误
用npm uninstall typescript卸载，显示：up to date, audited 1 package in 286ms，found 0 vulnerabilities
再安装也是和刚开始一样的错误