how to center plotly plot title

import plotly.graph_objects as go

fig = go.Figure()

fig.update_layout(
    title="Plot Title",
    xaxis_title="x Axis Title",
    yaxis_title="y Axis Title",
    font=dict(
        family="Courier New, monospace",
        size=18,
        color="#7f7f7f"
    )
)

fig.show()

fig.update_layout(title_text='Your title', title_x=0.5)