Error “require ext-xml” in ubuntu command composer update or install

Problem 1
– laravel/pint[v1.0.0, …, v1.13.9] require ext-xml * -> it is missing from your system. Install or enable PHP’s xml extension.
– Root composer.json requires laravel/pint ^1.0 -> satisfiable by laravel/pint[v1.0.0, …, v1.13.9].

Solution :- 

sudo apt-get install php-xml