MongoError: Expression $ne takes exactly 2 arguments. 1 were passed in… may i know where is the error?

Question

fitness_goals.aggregate([{\'$match\':{status:1,_id:{\'$in\':[5f606c24dedd8512595cbf32,]}}},{\'$unwind\':\'$recommendedRecipe\'},{\'$group\':{_id:null,recipeId:{\'$addToSet\':\'$