exampleapi.php

$url  = "https://v3.openstates.org/jurisdictions';
$args = array(
  'headers' => array (
     'X-API-KEY' => 'your api key here'
   ),
);

$response         = wp_remote_get(  $url, $args );
$response_code    = wp_remote_retrieve_response_code( $response );
if ( 200 != $response_code ) {
			// handle non sucess  e.g. error_log
}
$decoded = json_decode( wp_remote_retrieve_body( $response ), true );   // decodes json into an array