Is two-factor authentication required to upload iOS app to App Store

In an effort to keep your account more secure, two-factor authentication will be required to sign in to your Apple Developer account and Certificates, Identifiers & Profiles starting February 27, 2019. This extra layer of security for your Apple ID helps ensure that you're the only person who can access your account.

Please refer the below link

https://support.apple.com/en-gb/HT204915

I face same issue, but we can export the ipa file instead of directly uploading from Xcode and then upload ipa file via application loader. It worked for me.