`echarts4rBox()` error - `object 'x' not found`

[jack-davison]

packageVersion("echarts4r")
#> [1] '0.4.5.9000'

echarts4rBox(cars, speed, dist, "Cake", type = "bar")
#> Error in echarts4rBox(cars, speed, dist, "Cake", type = "bar"): could not find function "echarts4rBox"

^{Created on 2025-06-18 with reprex v2.1.1}

Also occurs with CRAN release version.

Example taken from https://echarts4r.john-coene.com/articles/boxes.