Certificates google play console

I compiled an app and sent it to Google Play, I needed to update it and did a new build. When I sent it he gave this error talking about a certificate. How can I fix this? Thanks.

You have sent an unsigned APK with the upload certificate. You must use the same certificate. The upload certificate has the fingerprint:
SHA1: 21: 29: A2: 0A: 3C: 57: CC: 44: B6: 21: CB…
, and the certificate used to sign the submitted APK is fingerprinted:
SHA1: A4: CE: 4E: 84: 7D: 93: 94: 8F: 93: 7E: 89:…

My voltbuilder.json:

    "androidDname": "cn=myname, ou=mygroup, o=mycompany, c=mycountry",
    "platform": "android",
    "release": "release"

Tip : If you’re pasting code, html or config files, surround the code with triple back ticks (```), before the first line and after the last one. It will be formatted properly.

To replace an existing app, you need to use the same keystore time. Since you’re not supplying a keystore file, VoltBuilder uses the androidDname information to create a new keystore each time.

There’s more on setting up the keystore file here.