Typescript; push ObjectId into an arr[ ]

HOW DO I PUSH OBJECTID OF A DOCUMENT TO ANOTHER IN MONGOOSE

HOW DO I PUSH OBJECTID OF A DOCUMENT TO ANOTHER IN MONGOOSE

..... I have a collection for categories and it has an

Array[ ]

Array[ ]

of Brands that only takes in

ObjectId

ObjectId

of brands, i typed the brand as

brand: ObjectId[ ]

brand: ObjectId[ ]

but the push method is not working, nothing is being pushed to the

brand Array[ ]

brand Array[ ]

inside the category.