The Text controls allow you to add a simple, single-line text input.
Example
new \Kirki\Field\Text(
[
'settings' => 'text_setting',
'label' => esc_html__( 'Text Control', 'kirki' ),
'section' => 'section_id',
'default' => esc_html__( 'This is a default value', 'kirki' ),
'priority' => 10,
]
);