Dropbox API not returning all files

public function login(Request $request)
    {
       if ($request->has('code')) {
            $data = [
                'code' => $request->input('code'),
                'grant_type' => 'authorization_code',
                'client_id' => env('DROPBOX_APP_KEY'),
                'client_secret' => env('DROPBOX_APP_SECRET'),
                'redirect_uri' => env('DROPBOX_REDIRECT_URI')
            ];
            $response = $this->api_client->request(
                'POST',
                '/oauth2/token',
                ['form_params' => $data]
            );

            $response_body = json_decode($response->getBody()->getContents(), true);
            
            $access_token = $response_body['access_token'];

            //dd($access_token); //I can access the token here

            return redirect('dashboard');
        }

        return redirect('/');
    }  

public function user(){

        $response = $this->adminRepo->apiClient->request('POST', '/2/users/get_current_account', [
            'headers' => [
                'Authorization' => 'Bearer ' . $this->adminRepo->accessToken
            ]
         //error : invalid authorization value in HTTP header "Authorization": " (truncated...)
        ]);

        $user = json_decode($response->getBody(), true);


        $page_data = [
            'user' => $user
        ];

        return view('admin.user', $page_data);
    }

Hey Greg, sorry about the post subject my bad.

Could you please take a look at above two methods in which I am trying to pass the access token generated by /oauth2/token but it returns null and throws an error of bad authorization header.Is there any possible way I can retrieve this token from within my other classes.

Thank you so much for your help. It means a lot me.