Upload Attachment with RequestManagement(OCMQ) Webservice
Yes, Web Services supports sending attachments into Service Manager. Please note that later versions of Service Manager (7.11+) include a number of enhancements and fixes for Web Services.
Web Services Best Practices Guide:
I have read the manual and I know that is possible to upload attachments to incidents, the problem I have is that I couldn't find how to upload attachments to ocmq with webservices
Service Manager supports sending attachments via Web Services for any file that contains a single unique key. However, Request Management is not configured out-of-the-box to work with Web Services.
Consider reviewing this thread which contains information on extaccess records: