Chat can be enabled in video properties.

client/common-client-plugin.ts

@@ -1,5 +1,5 @@
 
-function register ({ registerHook }: RegisterOptions): void {
+async function register ({ peertubeHelpers, registerHook, registerVideoField }: RegisterOptions): Promise<void> {
   registerHook({
     target: 'action:router.navigation-end',
     handler: () => {
@@ -9,6 +9,34 @@ function register ({ registerHook }: RegisterOptions): void {
       }
     }
   })
+
+  const [label, description, settings] = await Promise.all([
+    peertubeHelpers.translate('Use chat'),
+    peertubeHelpers.translate('If enabled, there will be a chat next to the video.'),
+    peertubeHelpers.getSettings()
+  ])
+  const webchatFieldOptions: RegisterClientFormFieldOptions = {
+    name: 'livechat-active',
+    label: label,
+    descriptionHTML: description,
+    type: 'input-checkbox',
+    default: true,
+    hidden: ({ liveVideo }) => {
+      if (!liveVideo) {
+        return true
+      }
+      if (!settings['chat-per-live-video']) {
+        return true
+      }
+      if (settings['chat-all-lives']) {
+        // No need to add this field if live is active for all live videos
+        return true
+      }
+      return false
+    }
+  }
+  registerVideoField(webchatFieldOptions, { type: 'update' })
+  registerVideoField(webchatFieldOptions, { type: 'go-live' })
 }
 
 export {