My Apple Watch is not working with tattoos

Hello~ Have a look here by clicking on below…

Get the most accurate measurements using your Apple Watch - Apple Support*

*Permanent or temporary changes to your skin, such as some tattoos, can also impact heart rate sensor performance. The ink, pattern, and saturation of some tattoos can block light from the sensor, making it difficult to get reliable readings.

~Katana-San~

Opaque ink is blocking the light sensor from seeing under your skin.