> For the complete documentation index, see [llms.txt](https://doc.duaer.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.duaer.com/integrations/builtin/app-nodes/duaer-nodes-base.notion/common-issues.md).

# Common issues with Notion in Duaer

Common Notion node issues in Duaer: missing relation properties, toggle headings, and empty-value validation errors.
## Relation property not displaying <a href="#relation-property-not-displaying" id="relation-property-not-displaying"></a>

The Notion node only shows two-way relations. In Notion, edit the relation property and turn on Show on <related database>. For a one-way relation, send a PATCH to https://api.notion.com/v1/pages/<page_id> from [HTTP Request](/integrations/builtin/core-nodes/duaer-nodes-base.httprequest.md) with the same Notion credential.

## Create a toggle heading <a href="#create-toggle-heading" id="create-toggle-heading"></a>

The Notion node can add Heading 1 to 3 but cannot make them toggleable. Add the heading with the Notion node, then send a PATCH to https://api.notion.com/v1/blocks/<block_id> from HTTP Request (Predefined Credential Type set to your Notion credential) with body {"heading_1": {"is_toggleable": true}}, swapping heading_1 for your level.

## Empty values fail validation <a href="#handle-null-and-empty-values" id="handle-null-and-empty-values"></a>

When a field takes its value from an earlier node and that item has no data, Notion rejects the empty or null value. Check with [If](/integrations/builtin/core-nodes/duaer-nodes-base.if.md) first and drop the field with Edit Fields (Set), or give the expression a default.
## Questions

### Why can’t the Duaer Notion node see a relation property?

The Duaer Notion node only shows two-way relations. Turn on Show on <related database> for the relation in Notion.