URL error: Verify if the URL is correct, including the protocol, hostname, and path sections.
Network issue: Ensure that the server is working properly and accessible.
Restricted internet access: If the server has set access restrictions, you may need to provide the correct authentication information or use a proxy server.
HTTPS certificate issue: If the target website is using HTTPS protocol, there may be certificate verification errors. You can bypass the certificate verification by setting curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false).
Redirecting issue: If the destination website returns a redirect response, you need to set curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true); to automatically follow the redirect.
Issue with request headers: Some websites may have restrictions on request headers, so it is necessary to configure the appropriate request header information.
Server response issue: Sometimes the server may return either an empty response or an incorrect response, debugging should be done based on the specific situation.
PHP configuration issue: Check if the cURL extension is enabled in the PHP configuration and if the relevant settings are correct.
Other possible issues: there may be other unknown issues that can be investigated by checking error logs, debugging output, and other methods.
