Question about ASUS ROG Swift PG259QN

Hello, My RGB on the monitor I just bought doesn't work somehow. At the very beginning when I started the monitor a small window appeared briefly in the middle of the screen where it said RGB on/off I couldn't do anything in time if anything had worked at all and went into the settings: Light effect Aura Sync on It didn't work so I tried it with: Aura RGB I tested all the functions there and nothing happened. I hope someone can help me