using s3 storage Class 'SimpleXMLElement' not found

I am using digital ocean server and my site is in laravel and php 7.2 site is working fine but now I want to use amazone S3 storage space while I am entering s3 credentials in env file and run this site then it is showing this error

 ErrorException in PayloadParserTrait.php line 44: 
 Class 'SimpleXMLElement' not found (View: /var/www/xxxxxxxx/xxxxxxxxx/resources/views/home/index.blade.php)

please help me out about this problem.

but when I use these credentials in local host it is showing this error

ErrorException in WrappedHttpHandler.php line 195: 
Error executing "ListObjects" on "https://astrochest.s3.amazonaws.com/?prefix=cache%2Fcad2dc21%2Faveec8569429dbfa0cc9b.jpeg%2F&max-keys=1&encoding-type=url"; AWS HTTP error: cURL error 60: SSL certificate problem: unable to get local issuer certificate (see https://curl.haxx.se/libcurl/c/libcurl-errors.html) (View: E:\wamp64\www\newastrochest\astrochest\resources\views\home\index.blade.php) 

via Chebli Mohamed