showProgress

fun MaterialButton.showProgress(@ColorInt tintColor: Int = this.iconTint.defaultColor)(source)

Source: https://stackoverflow.com/questions/70954321/circular-progress-indicator-inside-buttons-android-material-design

Shows indeterminate progress bar on this button in place of where icon would be. By default the tint of progress bar is the same as iconTint.

tintColor

(@ColorInt Int) Sets custom progress bar tint color.