Italicizing strip.text with ggplotly

I've been trying to get the labels on a faceted grid to be italicized on the y-axis and can't seem to make it to happen.

Here I'll use the "Free Y Axis" example of a faceted grid as written by Plotly:
https://plotly.com/ggplot2/facet_grid/

The only change I've made to this code is make the strip text for both axes larger and the y-axis text italicized in the ggplot theme().

library(reshape2)
library(ggplot2)
library(plotly)

p <- ggplot(tips, aes(x=total_bill)) + geom_histogram(binwidth=2,colour="white")

# With panels that have the same scaling, but different range (and therefore different physical sizes)
p <- p + facet_grid(sex ~ smoker, scales="free", space="free") +
               theme(strip.text.x = element_text(size = 13),
               strip.text.y = element_text(size = 13,face = "italic"))

p

fig <- ggplotly(p)

fig

The plot produced by ggplot (p) looks like this, with the y-axis facet labels in italics:

The plot produced by ggplotly (fig) looks like this:

Any clarification if I'm missing something would be appreciated. Thank you!

提供されている「Free Y Axis」の例から始め、ggplot オブジェクト p と ggplotly の結果 fig を比較し、facet strip テキストのスタイルがどのように変換されるかに注目してください。y 軸の facet ラベルに欠けているイタリック体のスタイルを再現してください。ggplotly が大きい strip テキストを維持しながらイタリック体の書体も保持すれば完了です。