Hi, thanks for your answers. We have verified our Network Extension plugin now, using a profile configuration as described here and made in Apple Configurator 2, our iOS app is downloaded via TestFlight on a supervised iOS device. Works as expected :) Thanks!

Should work as I dont need to open my app on the managed device for enabling the web content filter? Here is my com.apple.webcontent-filter payload  <dict> <key>UserDefinedName</key> <string>ProTective Web Content Filter</string> <key>PayloadDescription</key> <string>WebContentFilterSettings</string> <key>PayloadIdentifier</key><string>com.apple.webcontent-filter.96980f60-3b6b-45fa-8555-9d6e58a50666</string> <key>PayloadUUID</key><string>96980f60-3b6b-45fa-8555-9d6e58a50666</string> <key>PayloadType</key><string>com.apple.webcontent-filter</string> <key>PayloadVersion</key><integer>1</integer> <key>FilterDataProviderBundleIdentifier</key> <string>extension.FilterDataProvider.BundleIdentifier</string> <key>FilterDataProviderDesignatedRequirement</key> <string>extension.FilterDataProvider.DesignatedRequirement</string> <key>FilterPackets</key> <false/> <key>FilterBrowsers</key> <true/> <key>FilterSockets</key> <true/> <key>FilterType</key> <string>Plugin</string> <key>PluginBundleID</key> <string>my.app.bundle.id</string> </dict>

Yes the iOS device is supervised.

I want to enable the web content filter on a iOS device, iOS 12.x (I'm using Workspace one as MDM) Thanks for your reply.