setFillAlpha

open fun setFillAlpha(@FloatRange(from = 0.0, to = 1.0) alpha: Float)

Sets the annotation's fill alpha value if supported. It's the value in range <0.0f...1.0f>. NOTE: Added in v2024.6. Currently this API is the only way to change this value. If you need a UI for it, please contact support.