How to Upload a Document/File to an External API Using Multipart/Form-Data in Creatio?

Hi Community,

I am currently working on an integration where I need to upload documents/attachments from Creatio to an external API.

The external API expects the document to be sent using multipart/form-data in the request body payload.

The current integration flow is:

Creatio → Web Service → External API

However, I am unable to find an OOTB option to pass the actual file/document as a multipart/form-data request body parameter.

I would like to know:

1. Is it possible to send a file from Creatio to an external API as multipart/form-data using the OOTB Web Service functionality?
2. If not, what is the recommended approach to achieve this?
3. Can this be implemented using a Script Task or custom C# code in a Business Process?
4. Is there any recommended Creatio API or marketplace component that can help with uploading files to an external API using multipart/form-data?

Any guidance, sample code, or recommended approach would be greatly appreciated.

Thanks in advance for your help!