RShiny - export diagrammeR plot to powerpoint - r

Question

I have an RShiny application that generates a network plot using the diagrammeR package:
blc3001 <- eventReactive(input$datapath,{
data_blc <- readxl::read_xlsx(input$datapath$datapath)
blc3001 <- "digraph test{<TONS OF GRAPH CODE>"
})
I can output to Shiny using:
output$blc3001 <- renderGrViz({
grViz(blc3001())
})
And I can download as a .png using:
output$d_blc3001 <- downloadHandler(
filename = "blc3001.png",
content = function(file) {
grViz(blc3001()) %>% export_svg %>% charToRaw %>% rsvg_png(file)
},
contentType = "image/png"
)
Now I am trying to download this graph into a powerpoint slide, but am running into difficulty. I am open to any method or package, but I am currently trying to do this via the "officer" package.
output$blc3001_powerpoint <- downloadHandler(
filename = function() {
"blc3001.pptx"
},
content = function(file) {
image <- grViz(blc3001()) %>% export_svg %>% charToRaw %>% rsvg_png()
ppt_report <- read_pptx() %>%
add_slide(layout = "Title and Content", master = "Office Theme") %>%
ph_with(value = image, location = ph_location_type(type = "body"))
print(ppt_report, target = file)
}
)
Although I can download the png, when I define ppt_report, I get error:
Error in UseMethod("ph_with", value) :
no applicable method for 'ph_with' applied to an object of class "raw"
I assume this is because I specify content type is img/PNG in the image download handler, but not the powerpoint download handler. I can download the powerpoint without error if I remove "%>% charToRaw %>% rsvg_png()" from defining image, but the powerpoint slide contains the XML code rather than rendering the actual svg. If anyone can please provide any tips on how to proceed I would greatly appreciate it! Thanks!