Save Pattern ⇧⌘P
Save the pattern. The command is located in the tool (gear) menu in the Step Sequence. A whole new (old) place to explore.
My first MIDI software (after my CZ Editor) was Opcode Vision — a MIDI sequencer. This modern take on the step sequencer (every pattern is a step sequencer? recursion is us)
Logic Pro Step Sequencer overview — Apple Support
Step Sequencer patterns are contained in pattern regions (in the Tracks area) and pattern cells (in the Live Loops grid). Pattern regions and cells are used primarily on MIDI-based (software instrument, external instrument, and Drummer) tracks. Pattern regions (but not pattern cells) can also be used on audio tracks to automate effect and channel strip parameters. A project can contain any number of pattern regions or cells.
Each pattern region or cell functions as an independent step sequencer, with its own configuration and settings. You can copy and move pattern regions like other regions in the Tracks area, while pattern cells can be copied, moved, triggered, and queued like other Live Loops cells. You can modify pattern region and cell parameters in the Region inspector or Cell inspector, respectively.