According to the manual I received from the consignor,
ALIAS_KE.RSA/ALIAS_KE.SF is added when the jarsigner command is executed.
When I uploaded to Google Play Console, I was told that
ALIAS_KE.RSA/ALIAS_KE.SF cannot be used because the Level of SDK is 16-17.
When I unzipped the past apk given to me by the consignor, I found that it was signed with CERT.RSA/CERT.SF.
However, the consignor does not have any signing instructions left and I am having trouble.
How can I sign CERT.RSA/CERT.SF in the Android apk file?
The files in the META-INF directory (including *.RSA and *.SF) are never signed.
You haven't provided the exact error from the Play Console so difficult to say what exactly is going on, but the issue is likely to be that the strength of the key you used to sign the app is not supported on devices on Android SDK 16, and because your app must have minSdkVersion=16, those devices would not be able to install your app properly.
E.g. maybe you used SHA-256 as part of the signing algorithm but those devices only support up to SHA-1 or something like that.
You can have more information by running:
apksigner verify --verbose release.apk