How to use https://api.dropboxapi.com/2/files/copy_reference/save

Hello,

Thanks for the answer, can you please give me more explanations about this : 

• connect DB1app (the same app as above) to DropboxAcc2, resulting in AccessToken2

How can i connect my app to 2 differents accounts programmatically :

The only way to do it is like that ? :

Log in my browser with my email password to DropboxAcc1, then use Oauth flow with this code and App1 client_id and client_secret : 

    $tokenUrl = 'https://api.dropboxapi.com/oauth2/token';

    $tokenParams = http_build_query([
        'code' => $authorizationCode,
        'grant_type' => 'authorization_code',
        'client_id' => $clientId,
        'client_secret' => $clientSecret,
        'redirect_uri' => $redirectUri,
    ]);

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $tokenUrl);
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $tokenParams);
    curl_setopt($ch, CURLOPT_COOKIESESSION, true);
    curl_setopt($ch, CURLOPT_COOKIEFILE, '');
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_HTTPHEADER, [
        'Content-Type: application/x-www-form-urlencoded',
    ]);

    $tokenResponse = curl_exec($ch);
    $tokenResponse = json_decode($tokenResponse, true);
    curl_close($ch);

Here i got DropboxAcc1 token and i can get copy_reference of a file on DropboxAcc1

Then :

Logout MANUALLY my browser to DropboxAcc1 and login with DropboxAcc2 informations and use again the php code above.

Now iv got a second token and can use it to save file on DropboxAcc2.

I think i can do it like that, but i need to login and logout manually and this is not what i want...