"but what about ERC?"

It's a Wage Expense adjustment. It's not also on the balance sheet like PPP.

"If the corporation claims a credit for any wages paid or incurred, it may need to reduce the amounts on lines 7 and 8. See Reducing certain expenses for which credits are allowable, earlier. Also reduce the amounts reported on lines 7 and 8 by the nonrefundable and refundable portions of the new CARES Act employee retention credit claimed on the corporation's employment tax return(s)."

From the 1120S instructions.

Here are examples:

https://proconnect.intuit.com/community/taxation/help/entering-the-employee-retention-credit/00/1217...

https://proconnect.intuit.com/community/proseries-tax-discussions/discussion/employee-retention-cred...