db={"products":[{"_id":{"$oid":"607a858c2db9a42d1870270f"},"code":"CODLV001","name":"Product Name","category":"607a63e5778bf40cac75d863","tax":"0","saleValue":"0","status":true}],"categories":[{"_id":ObjectId("607a63bf06e84e5240d377de"),"name":"Diversey Care","status":true},{"_id":ObjectId("607a63e5778bf40cac75d863"),"name":"Sani Tisu Profesional","status":true}]}

db.products.aggregate([{$addFields:{category:{$toObjectId:"$category"}}},{$lookup:{from:"categories",localField:"category",foreignField:"_id",as:"category"}}])