Trim an SSD in macOS

Apple macOS enables Trim for internal Apple SSDs only.  Advanced users can also enable Trim for USB connected SSDs with Apple APFS formatted partitions.  Apple macOS runs Trim when the file system is detected by the operating system, this is either on device connection or system restart, Apple does not provide a manual Trim tool like with Windows or Linux.

Trim an SSD in macOS - Plugable Knowledge Base