https://blog.clarence.tw/2023/03/04/dgx-%e7%b3%bb%e7%b5%b1-ubuntu-18-04-%e5%87%ba%e7%8f%be-no_pubkey-a4b469963bf863cc-%e8%a7%a3%e6%b1%ba%e6%96%b9%e6%b3%95/