Ask project owners to get the private GPG key and import it using command
gpg --import 64C54E61.asc
Configure the maven settings in ~/.m2/settings.xml
<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
http://maven.apache.org/xsd/settings-1.0.0.xsd">
<servers>
<server>
<id>ossrh</id>
<username>maestrano</username>
<password>ask_owner</password>
</server>
</servers>
<profiles>
<profile>
<id>ossrh</id>
<activation>
<activeByDefault>true</activeByDefault>
</activation>
<properties>
<gpg.executable>gpg</gpg.executable>
<gpg.keyname>Maestrano</gpg.keyname>
<gpg.passphrase>ask_owner</gpg.passphrase>
</properties>
</profile>
</profiles>
</settings>
Increment version in pom.xml
mvn release:prepare -DdryRun=true
mvn -Pgpg release:clean release:prepare release:perform
jdk_switcher home oraclejdk8
jdk_switcher use oraclejdk8
mvn clean package -Dgpg.passphrase=${GPG_PASSPHRASE}