How to grouped json and sum its score? i have make this approach but still stuck to addition the value.

I have this json value:

A = [ { name: 'Boy', score: 10}, { name: 'Marry', score: 90 }, { name: 'Boy', score: 70 } ]

i want to get the result json like this

Result = [ { name: 'Boy', score: 80 }, { name: 'Marry', score: 90 } ]

i tried this code but still failed to add the value

let grouped = Object.values(data.reduce((r, {nickname, score}) => {
                r[nickname] = r[nickname] || { nickname, score: [] };
                r[nickname].score =  r[nickname].score + score
                return r;
            }, {}))

            console.log(grouped);

the result is

Result = [ { name: 'Boy', score: '1070' }, { name: 'Marry', score: '90' } ]

it converted to string :( Please help me