There already is a line in the file that is commented out.
remove the semi colon at the start. It’s near the top in the [Platforms] section.
Also, make sure you have Compile for Android devices selected in the Setup Assistant, and have installed any additional required SDKs.
If you find Compile for Android was not enabled and you needed to install additional requirements, you should reconfigure and recompile your project.
From the command line go to your dev directory.
lmbr_waf build_win_x64_vs2017_profile -p all --progress
lmbr_waf build_win_x64_vs2019_profile -p all --progress
depending on which version of Visual Studio you are using.