> ## Documentation Index
> Fetch the complete documentation index at: https://docs.omni.co/llms.txt
> Use this file to discover all available pages before exploring further.

# externalId

> Creates a unique ID for the embed user.

<Note>
  This parameter is **required** to create valid embed requests.
</Note>

In the **Embed URL Builder**, this is the **External ID** field.

## Syntax

```markdown theme={null}
externalId=<unique_id>
```

## Properties

<ParamField path="externalId" type="string" required>
  A unique alphanumeric identifier for the embed user.
</ParamField>

## Examples

```markdown title="Example externalId" theme={null}
externalId=ohtani17
```