shard_manager extension on PGXN

Hello,

Regarding this thread :
/messages/by-id/0683F5F5A5C7FE419A752A034B4A0B979778864A@sswchi5pmbx2.peak6.net

And after reading
https://pgxn.org/dist/shard_manager/0.0.1/doc/shard_manager.html#shard_manager.Extension

Column data for sharding not only series type , but also text or other
type.
And you don't present how to get the target partition through function
in usage section.
Would you mind releasing more details ?

Regards,
Steven