I am new to Drupal and am creating a custom theme, but for some reason, the Image Field option is missing when I try to add a new field in the 'Manage Fields' section under Block types. This is a fresh install using DDEV and Drush. Are there any settings I need to enable to make image field visible, or am I missing something?
Select "file upload" and you will be able to select an image field.
If you want to store images as entities, maybe you want to enable the media module.