frequently used 3 times

How can I make a function that outputs only 3 frequently used usernames from an object

        let allUser = await User.findAll()
        var result = {};
        allUser.forEach(function(v){
            result[v.age = result[v.age] + 1 || 1;
        })
        for (var key in result)
            console.log(key + result[key])
console.log('amount ' + key + ' == ' + result[key] + ' times <br>')

//amount 19 == 1 times 
//amount 15 == 1 times 
//amount 20 == 34 times 

I don't have 3 but all at once, I want it to sort But not more than 3.

1. 34
2. 1 
3. 1