To create and use custom visuals and R scripts in Power BI, you need to follow these steps:

* Create a custom visual in R : You can create a custom visual in R using a variety of R packages such as ggplot2, plotly, etc. Once you have created your custom visual, you need to wrap it in the powerBIVisuals package to make it compatible with Power BI. Here's a simple example of creating a bar chart in R:

library(ggplot2)
library(powerBIVisuals)

powerBIBar <- function(data, visualArgs) {
  p <- ggplot(data, aes(x = data$x, y = data$y)) +
    geom_bar(stat = "identity")
  powerBIVisual(p, visualArgs)
}​

* Package the custom visual : Once you have created your custom visual, you need to package it so that it can be easily imported into Power BI. You can do this by using the devtools package in R. Here's an example of how to package a custom visual :

library(devtools)

# Create a folder for your custom visual
create("myCustomVisual")

# Copy the code for your custom visual into a file called myCustomVisual.R

# Create a file called DESCRIPTION with the following content
Package: myCustomVisual
Type: Package
Title: My Custom Visual
Version: 0.0.1
Authors@R: person("Your Name", email = "your.email@example.com")

# Build the package
build()​

* Install the custom visual in Power BI: To install the custom visual in Power BI, you need to go to the Power BI Desktop Options dialog, select "Preview features", and then select "R script visuals". Then, you can install your custom visual by uploading the .pbiviz file that was created when you packaged your custom visual.

* Use the custom visual in Power BI: Once you have installed your custom visual, you can use it just like any other visual in Power BI. Simply select the visual in the "Visualizations" pane and add your data to the visual. You can also modify the visual using the Formatting pane.