koobas.hobune.stream
Android SDK is missing build-tools
I don't know why but in the Unity 2020.3.13 version, I was getting this kind of error dialog box when I try to export a build. 
I have downloaded the whole package from Unity HUB rather than doing any manual stuff and these are my External Tools screenshot: 
At present, I can't able to export android build because of this error message so please guide me to solve this.
This happened to me too, if you have Avast antivirus (or any other), turn it off and in the Unity Hub, in the Installs window reinstall the Unity version.
