Get and return value outside function - Nodejs - node.js

Question

I'm working on some method that have a callback with value, that I need to return and response, but value is null outside callback funciton
How can I solve?
async function createChannel(req) {
let user_id = req.query.user_id;
let chat_name = req.query.chat_name;
var chimesdkmessaging = new AWS.ChimeSDKMessaging({region: region});
var channel = null;
try {
let dateNow = new Date();
const params = {
Name: chat_name,
AppInstanceArn: config.aws_chime_app_istance,
ClientRequestToken: dateNow.getHours().toString() + dateNow.getMinutes().toString(),
ChimeBearer: await AppInstanceUserArn(user_id),
AppInstanceUserArn of the user making the API call.
Mode: 'RESTRICTED',
Privacy: 'PRIVATE'
};
chimesdkmessaging.createChannel(params, function (err, data) {
if (err) {
console.log(err, err.stack);
} // an error occurred
else {
console.log(data); // successful response
console.log('Assegno il canale: ' + data.ChannelArn);
channel = data.ChannelArn; // <----- VALUE I WANT TO RETURN OUTSIDE
}
});
} catch (e) {
return response({error: e}, 500);
}
return response({data: channel},200); // <---- but this channel is null
}

Answer 1

wrap with Promise
let user_id = req.query.user_id;
let chat_name = req.query.chat_name;
var chimesdkmessaging = new AWS.ChimeSDKMessaging({region: region});
let channel = null;
try {
let dateNow = new Date();
const params = {
Name: chat_name,
AppInstanceArn: config.aws_chime_app_istance,
ClientRequestToken: dateNow.getHours().toString() + dateNow.getMinutes().toString(),
ChimeBearer: await AppInstanceUserArn(user_id),
AppInstanceUserArn of the user making the API call.
Mode: 'RESTRICTED',
Privacy: 'PRIVATE'
};
channel = await new Promise((resolve,reject)=>{
chimesdkmessaging.createChannel(params, function (err, data) {
if (err) {
console.log(err, err.stack);
reject(err)
} // an error occurred
else {
console.log(data); // successful response
console.log('Assegno il canale: ' + data.ChannelArn);
resolve(data.ChannelArn)// <----- VALUE I WANT TO RETURN OUTSIDE
}
});
})
} catch (e) {
return response({error: e}, 500);
}
return response({data: channel},200); // <---- but this channel is null
}