Failure while signing an apk file

In my deployment stage of an app built with ionic5 + Angular I get a warning while signing the apk file. As a result it doesn’t generate the signed apk.

Here is the warning;

The signer’s certificate is self-signed.
No -tsa or -tsacert is provided and this jar is not timestamped. Without a timestamp, users may not be able to validate this jar after the
signer certificate’s expiration date (2048-11-10) or after any future revocation date.

How should I go about it?