How to install exactextractr in R

I'm trying to install exactextractr in R. First I got the wrong messages like "C++14 standard requested but CXX14 is not defined", after searching the internet I added the following code in R.

    dotR <- file.path(Sys.getenv("HOME"), ".R")
if (!file.exists(dotR)) dir.create(dotR)
M <- file.path(dotR, "Makevars")
if (!file.exists(M)) file.create(M)
cat("CXX14FLAGS=-O3 -std=c++14 -march=native -mtune=native -fPIC",
    "CXX14=C:/MinGW/bin/g++", # or clang++ but you may need a version postfix
    file = M, sep = "\n", append = TRUE)

But now I'm getting other errors which are "make: *** [D:/R-3.6.1/etc/i386/Makeconf:215: exact_extract.o] Error 1 make: *** [D:/R-3.6.1/etc/i386/Makeconf:215: raster_utils.o] Error 1 Content type 'application/zip' length unknown" and "ERROR: compilation failed for package 'exactextractr'"

Any help would be highly appreciated.

Has this been solved here?