Web scraping using the curl R library from CRAN using the statistics software R

I want to scrape the content this webpage with varying variables in the URL using the R curl library with some code like further down. However, in the browser Mozilla I can see the data but not get them with R:

library(curl)
urltxt <- "https://grouper.swissdrg.org/swissdrg/single?version=7.3&pc=1337_70_0_0_M_11_00_15_0_2018/08/07_2018/08/22_C18.4_C07_-_45.81.11$$&provider=acute&locale=de"
con <- curl(urltxt )
open(con)
# Get 3 lines
out <- readLines(con, n = 3)
cat(out, sep = "\n")