load data and set up custom projection in R Shiny (leaflet) - shiny

Question

I would like to load data and set up a custom projection in R Shiny. I am able to load the data but cannot get the projection right (ESPG:26916). I have searched but am not sure what I have missed. Help much appreciated.
Here is the code I have
library(leaflet)
library(tidyverse)
ui <- fluidPage(
column(
width = 4,
leafletOutput("mymap", width = 1400, heigh = 700)),
p(),
fileInput("in_file", "Input file:",
accept=c("txt/csv", "text/comma-separated-values,text/plain", ".csv", "Decimal seperator")),
actionButton("upload_data", "Visualize New points")#,
)
server <- function(input, output, session) {
visualize <- reactive({
if(input$upload_data==0) {
return(NULL)
}
df <- read.csv(input$in_file$datapath,
sep = ',',
header = TRUE,
quote = "#",
row.names = NULL)
epsg26916 <- leafletCRS(
crsClass = "L.Proj.CRS",
code = 'EPSG:26916',
proj4def = "+proj=utm +zone=16 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs",
resolutions = 2^(15:-1)
)
return(leaflet(df,
options = leafletOptions(crs = epsg26916)
) %>%
addProviderTiles(providers$Esri.WorldImagery,
options = providerTileOptions(noWrap = TRUE)) %>%
setView(-85.39310209, 42.41438242, zoom = 16) %>%
addCircleMarkers(~easting, ~northing,
group = "my data",
weight = 1, fillOpacity = 0.7, radius = 3) %>%
addLayersControl(overlayGroups = c("my data"))
)
})
output$mymap <- renderLeaflet({
visualize()
})
}
shinyApp(ui, server)