How do you query for “is not null” in Mongo?

Question

I would like to execute a following query:

db.mycollection.find(HAS IMAGE URL)

What should be the correct syntax?

Answer 1

Sharing for future readers.

This query worked for us (query executed from MongoDB compass):

{
  "fieldName": {
    "$nin": [
      "",
      null
    ]
  }
}