How to Configure Authentication for Web Activity Triggering ADF Pipelines via Azure REST API

Hello,

I am working on integrating Azure Data Factory (ADF) with external systems using Web Activities. I am specifically using a Web Activity to trigger ADF pipelines via the Azure REST API, as described in the official documentation here:

https://learn.microsoft.com/en-us/rest/api/datafactory/pipelines/create-run?view=rest-datafactory-2018-06-01

I can configure the request method and URL in the Web Activity, but I am unsure about the supported and recommended methods for authentication.

Could someone please clarify:

What are the possible ways to configure authentication in Web Activities when calling Azure REST APIs (such as for creating a pipeline run)?

Is it possible to use Managed Identity (System-assigned or User-assigned) directly within the Web Activity?

If not, what are the alternatives (e.g., service principal with token acquisition)?

Are there any best practices or security considerations when configuring authentication for this use case?

Thanks in advance for your help!