es6 promise - Javascript - access variable in then outside it's scope

I have the following Javascript and I am trying to access the content data out of the service scope, what's the best way to access that data?

Service
.getContent()
.then((content = {}) => {//access this content out of 'Service' scope})
.catch((error = {})  => {console.log('errror', error)})

I tried the following:

let data = null;
Service
.getContent()
.then((content = {}) => {data = content})
.catch((error = {})  => {console.log('errror', error)})
console.log(data);

But I get the error that data is undefined. How can I get the contents of content to data