add nuget.config file.
ADD
nuget.config
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+ <packageSources>
+ <add key="nuget.org" value="https://www.nuget.org/api/v2/" />
+ <add key="AvaloniCI" value="https://www.myget.org/F/avalonia-ci/api/v2" />
+ <add key="XamlBehaviors" value="https://www.myget.org/F/xamlbehaviors-nightly/api/v2" />
+ </packageSources>
+</configuration>
\ No newline at end of file

add nuget.config file.