Is it possible to make customannotation like axis marker annotation?

I want to make label on yAxis.
SCIChart provides AxisMarkerAnnotation, but I want to use CustomAnnotation because I need something custom.
So I tried drawing a CustomAnnotation on the yAxis but failed.
Android succeeds in drawing CustomAnnotation on the yAxis using the method below, but iOS doesn’t provide it?
On iOS, Can’t customAnnotation only set the value of the yAxis like AxisMarkerAnnotation?
Android was possible…

error message like this
Exception raised with reason: CALayer position contains NaN: [nan 248.71]. Layer: <CALayer:0x280c10bc0; position = CGPoint (0 0); bounds = CGRect (0 0; 0 0); delegate = <BTChart.CurrentPriceAnnotationView: 0x13d74d8f0; frame = (0 0; 0 0); layer = <CALayer: 0x280c10bc0>>; sublayers = (<_UILabelLayer: 0x282d15860>); opaque = YES; allowsGroupOpacity = YES; >