> ## Documentation Index
> Fetch the complete documentation index at: https://pleo-preview.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Authenticating Using API Keys

## Using API Keys in Curl

Specify the API key in the`-u` or `--user` flag. The password is an empty string.

Here is an example:

```bash theme={null}
curl --request GET -sL \\
     --url '<https://external.pleo.io/v1/installations/me>'\\
     -u 'enter the API key here'
```

## Using API Keys in a Graphical User Inteface (GUI) Tool

Here, we are using **Postman** for reference:

1. In the `Authorization` header of the request, select **Basic Auth** as the **Auth Type**.
2. In the `Username`, enter the API key.
3. In the `Password`, do not enter any value.

![using API keys in GUI](https://mintcdn.com/pleo-preview/9fviW8ylL77_jDwu/images/docs/Authentication-using-API-keys/using-API-keys-in-GUI.png?fit=max\&auto=format\&n=9fviW8ylL77_jDwu\&q=85\&s=b09b60361397350b28cf68f48115bfff)


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