It's a fairly rare material, but there are a few spots to check.
Lumidouce Bell Farming Route Guide - Genshin - Icy Veins
Where to find Lumidouce Bell in Genshin Impact: 3 best farming routes - Dot Esports
Where to find Lumidouce Bell in Genshin Impact: 3 best farming routes - Dot Esports
Genshin Impact: Lumidouce Bell Farming Route
Where to find Lumidouce Bell in Genshin Impact: 3 best farming routes - Dot Esports
Where to find Lumidouce Bell in Genshin Impact: 3 best farming routes - Dot Esports
Genshin Lumidouce Bell Location & How To Get - GameWith
All 121 Lumidouce Bell Locations - Efficient Farming Route - Chevreuse & Lynette Ascension Material
Lumidouce Bell Farming Route Guide - Genshin - Icy Veins
Genshin Lumidouce Bell Location & How To Get - GameWith