Return data from method in object - javascript-objects

Question

I have been trying to figure this one out and I'm not getting how to return the data to another method and call it so that I don't have to statically add the data into my request. I keep getting undefined data on my B2C method when I run it for the data returned from this.O_Auth. Any clues?
let obj = {
O_Auth(key, secret) {
const key = Key;
const secret = Secret;
const auth = "Basic " + new Buffer(key + ":" + secret).toString("base64");
request(
{
uri: "https://randomurl",
method: 'GET',
headers: {
"Authorization": auth
}
},
(err, res, body) => {
if (err) {
return err;
} else {
// console.log(body);
let response = JSON.parse(body);
let res = JSON.stringify(response.access_token)
return res;
}
}
);
},
B2C(params) {
console.log("Random " + this.O_Auth('first', 'second'));
let options = {
method: 'POST',
uri: 'https://randomurl',
headers: {
"Authorization": "Bearer " + this.O_Auth('first', 'second'),
"Content-Type": "application/json"
},
body: {
//values
},
json: true
};
rp(options)
.then(function (body) {
console.log(body);
})
.catch(function (err) {
console.log(err);
});
}
}

Answer 1

Ended up figuring out the asynchronous nature of JavaScript meant I was requesting data that was being evaluated later so I used a promise to get the data and output it first before using it in a subsequent promise that outputs the body. Changed the first request to request promise (rp) that returns the options that will be needed for that promise in the second method.
let obj = {
O_Auth(Key, Secret) {
const key = Key;
const secret = Secret;
const auth = "Basic " + new Buffer(key + ":" + secret).toString("base64");
let options = {
uri: "https://randomurl",
headers: {
"Authorization": auth
},
json: true
};
return rp(options)
},
B2C(param1, param2, param3...) {
this.O_Auth('first', 'second'))then(response =>{
let token = response.access_token;
let options = {
method: 'POST',
uri: 'https://randomurl',
headers: {
"Authorization": "Bearer " + token,
"Content-Type": "application/json"
},
body: {
//values
},
json: true
};
rp(options)
.then(function (body) {
console.log(body);
})
.catch(function (err) {
console.log(err);
});
}).catch(error => console.log(error));
}
}