as @Fabio_Ramohitaj noted above, please try using formatting when you post codes.
Your problem here is the one I quoted.
MongoDB uses JSON data structure (and Javascript). Curly braces are used to denote an object, and an object has to include key-value pairs.
Yet, in your query, yours is just some string inside curlies.
two solutions exist here:
- as @Adeola_Oladeinde2 wrote, make it a correctly formed object
- or use square brackets and make it an array:
customData: [ "some info" ]