Not able to install R library in PowerBI

[Anonymous]

Hi, 

I am trying to install R library in PowerBI R editor

If i write: 

install.packages('mice', lib=.libPaths())

I get error message that

the lib element  C:\Program Files\R\R-3.6.2\library is not a writable directory

If i write

install.packages('mice')

I get

Error Message:
R script error.
Installing package into 'C:/Users/my name/Library'
(as 'lib' is unspecified)
Error in contrib.url(repos, "source") :
trying to use CRAN without setting a mirror
Calls: install.packages -> contrib.url
Execution halted

If i write

install.packages("plotrix", lib = "C:/Program Files/R/R-3.6.3/library")

I get the same error message as above.

What should I do???

Thanks in advance!