The ERP holds the records that matter most to operations and finance, so most valuable automation eventually touches it. Common examples include entering supplier invoices, matching them to purchase orders, updating stock and checking order status for customers.
For example, an AI document workflow could read incoming invoices, match each one to a purchase order in the ERP and send only the mismatches to accounts payable. The limit is that ERPs are often heavily customized and tightly controlled, for good reason. Integrations should use the ERP's supported APIs, write only what they must and leave posting or approving transactions to people with the right permissions.