1. memcached extension: Memcached is a high-performance distributed in-memory object caching system for dynamic web applications to reduce database load. Memcached is based on a hashmap that stores key/value pairs. its daemon is written in C, but clients can write it in any language and communicate with the daemon via the memcached protocol.
2. The memcached extension is PHP version specific, for php versions less than 7.2, memcached uses version 2.2.0, for php versions greater than or equal to 7.2, memcached uses version 3.2.0
3. If not installed, click Operation->Install to install memcached extension
4. After installation, you can click Operation->Copy Link, copy the extension link code and paste it into PHP configuration file to use memcached extension
5. After changing the PHP configuration file, remember to click Restart or Reload Configuration in the Services section to make the configuration take effect