[MM-67143] cherry pick of #34922 (#35800)

Automatic Merge

server/i18n/en.json

@@ -679,6 +679,14 @@
     "id": "api.command.execute_command.not_found.app_error",
     "translation": "Command with a trigger of '{{.Trigger}}' not found. To send a message beginning with \"/\", try adding an empty space at the beginning of the message."
   },
+  {
+    "id": "api.command.execute_command.provided_site_url_different.app_error",
+    "translation": "Request hostname differs from configured SiteURL. The configured SiteURL will be used for the slash command response URL."
+  },
+  {
+    "id": "api.command.execute_command.site_url_required.app_error",
+    "translation": "SiteURL must be configured to use slash commands"
+  },
   {
     "id": "api.command.execute_command.start.app_error",
     "translation": "No command trigger found."