I found my answer. It is not an amendment until after the filing deadline, it is a superseded return. In either case, it must be mailed in.
https://www.irs.gov/businesses/corporations/amended-and-superseding-corporate-returns
https://ttlc.intuit.com/community/business-taxes/discussion/how-do-i-e-file-a-superseded-1120s-retur...
View solution in original post
