tinyMice Editor only one line

Can you show me what you mean by 1 line?

You can make it a regular text field with this code:

add_filter( 'submit_job_form_fields', 'custom_submit_job_form_fields' );

function custom_submit_job_form_fields( $fields ) {
$fields['job']['job_description'] = 'textarea';
return $fields;
}

Hello Mike,
where I have to copy the code? in the themes/functions.php or the wp-job-manager/templates/form-fields/wp-editor-field.php.
yes I need the regular WP-editor
thank you for help.

This would go in functions.

This is to remove the WP Editor that it has by default and replace it with a text box (like you type into here).