To install the Imagick extension in DirectAdmin use this steps.
1) Install dependencies:
yum install ImageMagick ImageMagick-devel -y
2) Install PHP extensions with pecl:
/usr/local/php56/bin/pecl install imagick /usr/local/php72/bin/pecl install imagick
3) Load new compiled extensions:
echo "extension=imagick.so" > /usr/local/php56/lib/php.conf.d/11-imagick.ini echo "extension=imagick.so" > /usr/local/php72/lib/php.conf.d/11-imagick.ini
4) Restart/reload php-fpm services:
systemctl reload php-fpm56 systemctl reload php-fpm72