Dropbox SDK JS + Refresh token problem

Hello

Please, do you have any idea how i can manage this ? Each 4 hours i get "expired_access_token" and user must re-log.

I just upgrade my old Dropbox SDK JS to the last version 10.8.0 + I did the changes to be compatible.

I have one Cordova app (iOS/Android/Win10).

The goal of my app is to : 1. User connect on dropbox (long life), user set "working hours" on my app, then each day/week user save/load data to/from Dropbox.

Here's my code:

Connexion code:

// 1. I init Dropbox connexion
dbx = new Dropbox.Dropbox({
  clientId: dropboxClientId
});



// 2. I get auth url with redirect (custom url scheme)
var dropboxRedirectUri = 'MYAPP://dropbox_callback';

dbx.auth.getAuthenticationUrl(
  dropboxRedirectUri,
  '',
  'code',
  'offline',
  [
    'files.content.write',
    'files.content.read',
  ],
  'user',
  true
)
.then((authUrl) => {
  dropboxCodeVerifier = dbx.auth.codeVerifier;
  cordova.InAppBrowser.open(authUrl, '_system');
});

// 3. User is redirect to his web browser to logoff, then user is redirected to my app
function handleOpenURL(url) {
  // I read the "code" send by Dropbox
  if (getUrlVars(url).code) {
   dbx.auth.setCodeVerifier(dropboxCodeVerifier);
   dbx.auth.getAccessTokenFromCode(dropboxRedirectUri, getUrlVars(url).code)
   .then((response) => {
      // I get the "access_token" (starts with sl as short-life)     
      localStorage['dropbox_access_token'] = response.result.access_token;
   })
   .then((response) => {
     ... User is now connected
   })
   .catch((error) => {
     alert(error);
    });
}

// At this point, i also get "refresh_token", but I'm sorry i don't know how to use it.
// So, after that, for each user action (save/load) i connect to dropbox + i launch my // actions with this code:

dbx = new Dropbox.Dropbox({
  accessToken: localStorage['dropbox_access_token']
});
dbx.filesUpload({...	



Best regards