This is not working…

I followed the steps
sudo apt-get update
sudo apt-get install php5-xml

still got error

root@mint:~# sudo apt-get install php5-xml
Reading package lists… Done
Building dependency tree

Reading state information… Done
E: Unable to locate package php5-xml

apt-get install php-xml

These modules are packaged separately by Ubuntu (assuming that you are using Ubuntu).

The following should resolve the problem:

Ubuntu 14.04

sudo apt-get update 
sudo apt-get install php5-xml

Ubuntu 16.04

sudo apt-get update 
sudo apt-get install php7.0-xml

Hello, all

In order to install XMLWriter on Ubuntu use:

sudo apt-get install php-xml

and then restart your web server (Apache/Nginx)

If you want to install it for specific PHP version you can use this command:

sudo apt-get install php7.3-xml

and then again restart your web server.

For CentOS:

yum install libxml2

yum install php-xmlwriter

yum install php-xml

Once this is done you’ll need to restart the web server.

You can also check with a phpinfo file if the extension is enabled or use the following command in your terminal:

php -i | grep xmlwriter

The output should be:

root@digitalocean:~# php -i | grep xmlwriter
/etc/php/7.2/cli/conf.d/20-xmlwriter.ini,
xmlwriter

Hope that this helps!
Regards,
Alex