Meta Key on Windows 10 for R Command line editor

Question

I am using Windows 10.

> sessionInfo()
R version 3.4.2 (2017-09-28)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 15063)

Matrix products: default

locale:
[1] LC_COLLATE=English_India.1252  LC_CTYPE=English_India.1252   
[3] LC_MONETARY=English_India.1252 LC_NUMERIC=C                  
[5] LC_TIME=English_India.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

loaded via a namespace (and not attached):
[1] compiler_3.4.2

Below are the horizontal motion of the cursor for R command line editor. I was able to implement the one with C's below, C indicates Control Key, M indicates Meta key.

  C-a Go to the beginning of the command.
  C-e Go to the end of the line.
  M-b Go back one word.
  M-f Go forward one word.
  C-b Go back one character.
  C-f Go forward one character.

I tried pressing Esc b and Esc m not successful, tried other keys too..

How can I implement shortcut M-b and M-f to go back one word and go forward one word.