r - 安装了Rtools，R说没有安装

Question

我已按照此处的说明进行操作

https://cran.r-project.org/bin/windows/Rtools/

当我在 jsonlite 包上运行测试时，我仍然得到

WARNING: Rtools is required to build R packages but is not currently installed. Please download and install the appropriate version of Rtools before proceeding:

接着

Error: ERROR: no permission to install to directory 'C:/Users/fl014036/Documents/R/R-3.6.2/library'
Warning in install.packages :
  installation of package ‘jsonlite’ had non-zero exit status