Embed_url changing on update

I am including a filename in my call to plotly_POST, which, according to the docs, should update the plot but allow the URL to persist. However, the embed_url is changing every time I update the data, thus breaking all the links in my html. I even get a message asking if I want to overwrite the existing chart.

I don’t want to have to manually update the html every time I push updated data…what am I doing wrong?

Here are my calls:
p <- plot_ly(data = riskopp, x = ~risk, y = ~opp, text = riskopp$trend, marker = list(size = 10))
chart_link <- plotly_POST(p, filename=“riskopp”)

Thanks!