Files with spaces in file name in rshiny www directory

I have a question regarding embedding pdf or any other files for the matter within the shiny app. I have certain files (which cannot be renamed) with spaces in the file names, like, "report client 0056.pdf". I have embedded them using tags$iframe in the shiny app.

The browser returns Error 409, Not Found, when I embed such files, but files without any space in the name work without any issue. When I inspect the html code in the browser, the spaces in the file names are encoded as %20, but the browser is not able to process that. Do you have any work around for this problem?

Here is the error:

http://127.0.0.1:6323/report%20client%200056.pdf

Failed to load resource: the server responded with a status of 404 (Not Found)

Here is the shiny script:

PDFfile="report client 0056.pdf"
output$view <- renderUI({
        tags$iframe(
        src=PDFfile,
        width="100%",
        height="1200px")
      })