Charles Ellicott Commentary Joshua 8:30-31

"Then Joshua built an altar unto Jehovah, the God of Israel, in mount Ebal, as Moses the servant of Jehovah commanded the children of Israel, as it is written in the book of the law of Moses, an altar of unhewn stones, upon which no man had lifted up any iron: and they offered thereon burnt-offerings unto Jehovah, and sacrificed peace-offerings." — Joshua 8:30-31 (ASV)

An altar ... in mount Ebal ... —This was explicitly commanded in Deuteronomy. The blessing was put on mount Gerizim, the altar and the curse on mount Ebal. We do not hear elsewhere of any sacrifice on Ebal. But it is certain that God accepted sacrifices in many places in Canaan. (Compare to Exodus 19:24.)