set env variable from secret

.drone.yml

@@ -14,8 +14,11 @@ steps:
 
 - name: deploy
   image: mcr.microsoft.com/dotnet/core/sdk:3.1
+  environment:
+    API_KEY:
+      from_secret: API_KEY
   commands:
-    - dotnet nuget push /build/Structs/bin/Release/MoonTools.Core.Structs.*.nupkg -k $API_KEY -s https://api.nuget.org/v3/index.json
+    - dotnet nuget push /build/Structs/bin/Release/MoonTools.Core.Structs.*.nupkg -s https://api.nuget.org/v3/index.json -k $API_KEY 
   when:
     ref:
     - refs/tags/*.*.*