wordpress – Child Theme Generator Uncaught Error: Call to undefined function imagettftext()

Estoy tratando de crear un tema en wordpress con el plugin child teme generator pero estoy obteniendo este error:

WordPress Error: There has been a critical error on your website. Please check your site admin email inbox for instructions.

En el correo electrónico estoy obteniendo esta información:

An error of type E_ERROR was caused in line 453 of the file /opt/bitnami/apps/wordpress/htdocs/wp-content/plugins/child-theme-generator/includes/class-child-theme-generator-functions.php. Error message: Uncaught Error: Call to undefined function imagettftext() in /opt/bitnami/apps/wordpress/htdocs/wp-content/plugins/child-theme-generator/includes/class-child-theme-generator-functions.php:453
Stack trace:

#0 /opt/bitnami/apps/wordpress/htdocs/wp-content/plugins/child-theme-generator/includes/class-child-theme-generator-functions.php(287): Ch_Th_Gen_Functions::create_screenshot_png()

#1 /opt/bitnami/apps/wordpress/htdocs/wp-content/plugins/child-theme-generator/admin/class-child-theme-generator-admin.php(197): Ch_Th_Gen_Functions::files_generation()

#2 /opt/bitnami/apps/wordpress/htdocs/wp-content/plugins/child-theme-generator/admin/partials/child-theme-generator-admin-display.php(61): Ch_Th_Gen_Admin->section_create()

#3 /opt/bitnami/apps/wordpress/htdocs/wp-content/plugins/child-theme-generator/admin/class-child-theme-generator-admin.php(133): include_once(‘/opt/bitnami/ap…’)

#4 /opt/bitnami/apps/wordpress/htdocs/wp-includes/class-wp-hook.php(287): Ch_Th_Gen_Admin->display_options_page()

#5 /opt/bitnami/ap