Release management does not have a container for build artifacts, that's why you see this error message.
You can try with following task:
Write-host "##vso[task.uploadfile]<filename>"
View and download attachments associated with releases
Would you like to upload additional logs or diagnostics or images when
running tasks in a release? This feature enables users to upload
additional files during deployments. To upload a new file, use the
following agent command in your script:
Write-host "##vso[task.uploadfile]"
The file is then available as part of the release logs. When you
download all the logs associated with the release, you will be able to
retrieve this file as well.
You can also add a powershell script task in your release definition to read the log files and output it to the console. Then you will be see the content of the log files from "Logs" tab powershell script step. And you can also click "Download all logs as zip" to download the logs.