What is the field meta key option
The support for custom fields for users in WordPress is limited and it isn't possible to define new custom fields without a plugin like WP User Manager. WP User Manager, with the Custom Fields addon allows site admins to define custom user meta that they can add to user registration forms to collect data from users, as well as being displayed on the user profiles.
WP User Manager is one of the most straightforward to use WordPress membership plugins available, with a large number of features that turn your WordPress site into a membership platform.
Every field has a "unique meta key" setting that must be filled. This is automatically created for you when you create the field. The meta key determines how the field will be stored into the database of your website. If you do not need to do any custom development you probably do not need to customize this field.
This means that the full metakey name is wpum_field_11. If you change that to anything else like "job_title", the metakey will be wpum_job_title.
Here you can find an example of the get_user_meta function retrieving a WPUM field value.
get_user_meta( $user_id, 'wpum_field_11', true );
OR, if the above does not work:
carbon_get_user_meta( $user_id, 'wpum_field_11' );