Problem solved when installing R 3.5.1 64bit. After it, I typed:
avail <- installed.packages()[, 1]
neeeded <- c("grid", "maptools", "raster", "adehabitatHR", "adehabitatLT", "ggplot2", "graphics", "gridExtra", "KernSmooth", "lubridate", "mixtools", "mvtnorm", "rgdal", "rgeos", "reshape2", "sp", "spacetime", "stringr", "trajectories", "zoo", "shiny", "knitr", "markdown", "testthat", "shinyBS", "brew", "xtable")
install <- needed[!needed %in% avail]
if (length(install) > 0) { install.packages(install) }
Then, I have installed rhr package. Once unpacked I typed
library(rhr)
rhrGUI()
And the interface opens automatically in your internet browser.
Many thanks for your responses.