I just did a health check for my wordpress site , I was told to enable optional php module imagick , below is the steps

1.Install php 7 imagick module using below command

sudo apt-get update;sudo apt-get install php-imagick

2.Enable the installed module using phpenmod command

sudo  phpenmod imagick

3.Reload your http service to get it took affect to your wordpress site,I’m using apache2

sudo systemctl reload apache2.service

4.(optional) Redo healthcheck for your wordpress site , this time should be no such performance recommendation anymore