The missing ImageMagick extension is a common issue in aaPanel → PHP.
The solution is very simple. Just use the command below:
For CentOS
PHP 7.4
yum install lsphp74-imagick -y
PHP 8.1
yum install lsphp81-imagick -y
PHP 8.2
yum install lsphp82-imagick -y
PHP 8.3
yum install lsphp83-imagick -y
For DebianOS
PHP 7.4
apt install lsphp74-imagick -y
PHP 8.1
apt install lsphp81-imagick -y
PHP 8.2
apt install lsphp82-imagick -y
Restart your PHP service after installation.
You can confirm the ImageMagick installation from the PHP info page.