cURL error 60: SSL certificate problem

I am using spatie/flysystem-dropbox for backing up my Database on dropbox

But when I run the command, get an error

Copying zip failed because: cURL error 60: SSL certificate problem: unable to get local issuer certificate (see https://curl.haxx.se/libcurl/c/libcurl-errors.html)

I added curl.cainfo in php.ini but no effect taken

This is my filesystem.php

'disks' => [

    'local' => [
        'driver' => 'local',
        'root' => storage_path('app'),
    ],

    'public' => [
        'driver' => 'local',
        'root' => storage_path('app/public'),
        'url' => env('APP_URL').'/storage',
        'visibility' => 'public',
    ],

    's3' => [
        'driver' => 's3',
        'key' => env('AWS_ACCESS_KEY_ID'),
        'secret' => env('AWS_SECRET_ACCESS_KEY'),
        'region' => env('AWS_DEFAULT_REGION'),
        'bucket' => env('AWS_BUCKET'),
        'url' => env('AWS_URL'),
        'endpoint' => env('AWS_ENDPOINT'),
    ],

    'dropbox' => [
        'driver' => 'dropbox',
        'authorization_token' => env('DROPBOX_AUTH_TOKEN'),
    ],

],

I added in backup.php 'disks' => [ 'dropbox', ],

and this is my DropboxServiceProvider

Storage::extend('dropbox', function ($app, $config) { $client = new DropboxClient( $config['authorization_token'] );

        return new Filesystem(new DropboxAdapter($client));
    });

Thanks in advance