Return if array empty

I have this query

let filtrosEspeciales = await['sp-filtro'].find({
            _or: [{
                    'respuestas_in': respuestas
                    'respuestas': []

I want to return sp-filtro that have empty respuestas OR the respuestas that are in this variable(array) which I have called respuestas

This works for the second case, but it does not return for the first case

The first case should be

'respuestas': {
$in: respuestas

You’re using the old formatting, check out the updated filter docs here the relevant code snippets are in the dropdown areas with the note about the qs library.