Publish additional external jar-files to ossrh with maven - maven

Question

I want to publish my projects artifacts with maven to nexus. Therefore I followed this documentation which works for me for artifacts which are also build with maven. But now I want to publish additional artifacts (*.tgz files) which I download from somewhere else. I have not yet found out how to express in maven terms that I want to deploy those "local" artifacts.
What I tried is:
Create a new staging repo on ossrh with the pom file. This works and a new, open staging repository is created containing the pom file and a signature file.
> mvn deploy -DrepositoryId=ossrh
upload additional resources. This fails
> mvn deploy:deploy-file -Dfile=test-tst-0.0.1_linux-ppc64le_bin.tar.gz -Dclassifier=linux-ppc64le -DrepositoryId=ossrh -Durl=https://s01.oss.sonatype.org/content/repositories/iosapmachine-1031 -DgroupId=io.sapmachine -DartifactId=test-tst -Dversion=0.0.1
[INFO] Scanning for projects...
[INFO]
[INFO] -----------------------< io.sapmachine:test-tst >-----------------------
[INFO] Building io.sapmachine:test-tst 0.0.1
[INFO] --------------------------------[ pom ]---------------------------------
[INFO]
[INFO] --- maven-deploy-plugin:2.7:deploy-file (default-cli) # test-tst ---
Uploading to ossrh: https://s01.oss.sonatype.org/content/repositories/iosapmachine-1031/io/sapmachine/test-tst/0.0.1/test-tst-0.0.1-linux-ppc64le.gz
Uploading to ossrh: https://s01.oss.sonatype.org/content/repositories/iosapmachine-1031/io/sapmachine/test-tst/0.0.1/test-tst-0.0.1.pom
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 5.002 s
[INFO] Finished at: 2021-12-08T09:02:40+01:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-deploy-plugin:2.7:deploy-file (default-cli) on project test-tst: Failed to deploy artifacts: Could not find artifact io.sapmachine:test-tst:gz:linux-ppc64le:0.0.1 in ossrh (https://s01.oss.sonatype.org/content/repositories/iosapmachine-1031) -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
My pom.xml looks like this:
> cat pom.xml
<?xml version="1.0" encoding="utf-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<groupId>io.sapmachine</groupId>
<artifactId>test-tst</artifactId>
<version>0.0.1</version>
<name>${project.groupId}:${project.artifactId}</name>
<description>Test</description>
<packaging>pom</packaging>
<modelVersion>4.0.0</modelVersion>
<url>https://test.io/</url>
<licenses>
<license>
<name>GPLv2 + Classpath Exception</name>
<url>https://test/LICENSE</url>
</license>
</licenses>
<distributionManagement>
<snapshotRepository>
<id>ossrh</id>
<url>https://s01.oss.sonatype.org/content/repositories/snapshots</url>
</snapshotRepository>
<repository>
<id>ossrh</id>
<url>https://s01.oss.sonatype.org/service/local/staging/deploy/maven2</url>
</repository>
</distributionManagement>
<developers>
<developer>
<name>Test</name>
<email>test#test.com</email>
<organization>Test AG</organization>
<organizationUrl>http://www.test.com</organizationUrl>
</developer>
</developers>
<scm>
<connection>scm:git:https://github.com/test/tree/test-${project.version}</connection>
<url>http://github.com/test/tree/test-${project.version}</url>
</scm>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-gpg-plugin</artifactId>
<version>3.0.1</version>
<executions>
<execution>
<id>sign-artifacts</id>
<phase>verify</phase>
<goals>
<goal>sign</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>
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