This is documentation for an old release of Scikit-learn (version 1.2). Try the latest stable release (version 1.6) or development (unstable) versions.

sklearn.experimental.enable_hist_gradient_boosting

This is now a no-op and can be safely removed from your code.

It used to enable the use of HistGradientBoostingClassifier and HistGradientBoostingRegressor when they were still experimental, but these estimators are now stable and can be imported normally from sklearn.ensemble.