# Text substitution

This is the most basic example. This is what your JSON data should contain :

**Data**

{% code lineNumbers="true" %}

```json
{
  "firstname": "John",
  "lastname": "Doe"
}
```

{% endcode %}

<table data-header-hidden><thead><tr><th width="315.3333333333333"></th><th width="108" align="center"></th><th></th></tr></thead><tbody><tr><td><strong>Template</strong></td><td align="center"> </td><td><strong>Result</strong></td></tr><tr><td>Hello {firstname} {lastname} !          </td><td align="center"><span data-gb-custom-inline data-tag="emoji" data-code="27a1">➡️</span></td><td>Hello John Doe!</td></tr></tbody></table>

&#x20;In your template, the tags between curly braces will be replaced by the data you provided