Is aab's signature the same with apk file?

I'm making aab file for releasing.

We're using flutter.

Last release is uploading signed apk file to google play store,but this time for we can't upload 32bit and 64bit apk separately, so we tried to use appbundle.

We do have signature when we release apk file.

And because the release operation(upload apk file to google play) is handled by other team, so I don't know whether I need to use a new signature for aab file's release.

Here is my setting,just the same with last time

signingConfigs {
        release {
            keyAlias keystoreProperties['keyAlias']
            keyPassword keystoreProperties['keyPassword']
            storeFile file(keystoreProperties['storeFile'])
            storePassword keystoreProperties['storePassword']
        }
    }
    buildTypes {
        release {
            // TODO: Add your own signing config for the release build.
            // Signing with the debug keys for now, so `flutter run --release` works.
            signingConfig signingConfigs.release
        }
    }

and I have key.properties file

storePassword=XXX
keyPassword=XXX
keyAlias=XXX
storeFile=O:\\sourceCode\\key\\key.keystore

And for release, I set build variant as release, as introduced in flutter official doc

simply "No" you don't need new signature to create app bundle. your old signature will work fine