Rye invites you to battle his Lucario at the Training Grounds in Jubilife Village.

The Request

Talk to the Lucario in Galaxy Hall in Jubilife Village to accept this request.

Go to the Training Grounds

Go to the Training Grounds in Jubilife Village and talk to Rye. You can battle Lucario when you are ready.

Reward

After you win, you get a Grit Rock.