Add_annotation only shows at x=0 on a datetime64 x-axis

My Candlestick trace has a datetime64 x-axis.
I call add_annotation with a datetime64 value for X, and a market price for Y.
The time matches the 4th candle in the chart.
The text annotation Y position is correct, but it always appears at the far left edge of the chart, when it should be about 50-100 pixels inside the chart to match the time.
Am I doing something wrong?

After researching, I see I need to convert datetime64 to Timestamp. The chart xaxis must be doing that automatically. So I resolved this issue by calling pandas to_datetime for my x value in add_annotation…

import pandas as pd
fig.add_annotation(x=pd.to_datetime(mark_time),
                              y=mark_price,
                              text=label1,
                              showarrow=True,
                              arrowhead=1)