如何在Debian 10上安装PHP7.3？

$ sudo apt update 
$ sudo apt upgrade

$ sudo apt install ca-certificates apt-transport-https 
$ wget -q https://packages.sury.org/php/apt.gpg -O- | sudo apt-key add -
$ sudo echo "deb https://packages.sury.org/php/ buster main" | tee /etc/apt/sources.list.d/php.list

$ sudo apt update
$ sudo apt install php7.3

$ sudo apt install php7.3-cli php7.3-common php7.3-curl php7.3-gd php7.3-json php7.3-mbstring php7.3-mysql php7.3-xml

$ php -v

PHP 7.3.1-1 (cli) (built: Jan 13 2019 10:13:20) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.3.1, Copyright (c) 1998-2018 Zend Technologies
    with Zend OPcache v7.3.1-1, Copyright (c) 1999-2018, by Zend Technologies