Add the topic field to the page content type

config/core.entity_view_display.node.page.rss.yml

@@ -0,0 +1,38 @@
+uuid: a0be4283-4b23-418e-992d-f612b9ed25d8
+langcode: en
+status: true
+dependencies:
+  config:
+    - core.entity_view_mode.node.rss
+    - field.field.node.page.body
+    - field.field.node.page.field_body_paragraph
+    - field.field.node.page.field_meta_tags
+    - field.field.node.page.field_summary
+    - field.field.node.page.field_topics
+    - node.type.page
+  module:
+    - taxonomy
+    - user
+id: node.page.rss
+targetEntityType: node
+bundle: page
+mode: rss
+content:
+  field_topics:
+    type: entity_reference_rss_category
+    label: inline
+    settings: {  }
+    third_party_settings: {  }
+    weight: 3
+    region: ds_content
+  links:
+    settings: {  }
+    third_party_settings: {  }
+    weight: 100
+    region: content
+hidden:
+  body: true
+  field_body_paragraph: true
+  field_meta_tags: true
+  field_summary: true
+  search_api_excerpt: true