Are there discounts or promotions achievable for bulk purchases of Wuthering Waves Lunite on Manabuy?

https://www.scribd.com/document/987756795/Wuthering-Waves-Top-Up-vs-In-Game-Lunite-Price-What-You-Need-to-Know-128463

Are there coupon codes or promotions conceivable for bulk purchases of Wuthering Waves Lunite on Manabuy?