# Dynamic Data Source Selection
The Dynamic Data Source Selection popup allows you to customize dynamic data usage wherever needed. Data can be selected from:
* Previous actions
* Input payload
* Environment Secrets Manager
* Decoded tokens (e.g., user tokens)
#### Examples with Screenshots
**Using Email from Input Payload**:
* Select the email from the input payload of the API request.
* Use it for querying the database to check if the user exists.
Data is taken from input payload
**API Key from Secrets Manager**:
* Retrieve the API key for the SendGrid email service from the Secrets Manager.
* Use it securely for sending emails.
Data is taken from secrets manager
**Custom User Detail Handling**:
* Take user details from previous actions to build custom text.
* Return a custom object with data derived from the results of previous actions.
Data is taken from previous action results
This popup provides a flexible and intuitive way to manage dynamic data across various actions .
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# Agent Instructions: Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter:
```
GET https://docs.fireapis.com/the-basics/logics/dynamic-data-source-selection.md?ask=
```
The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.