Less Than Equal To

Filter::field('age', [FilterType::LESS_THAN_EQUAL_TO])

$filter = [
    'type'   => '$lte',
    'target' => 'age',
    'value'  => 18,
];

$sql = Person::filter([$filter])->toRawSql();

select * from "people" where "people"."age" <= 18