How to store object data in redis in nodejs rest service

I am trying to make rest web service in nodejs and using redis for caching purpose to improve performance. I want to save as a object like offer which has id, offer name and vendor.

I do not want to have different key to have for all these. What is the way to do in a single key.

app.get('/insertOffers', function(req, res) {
    const {id, offerName, offerVendor} = req.query;
    client.set('offers', ) // client is my redis client
});

via Williams