Any one can share me Installation & User Guide of Mobile Application Security Testing (MAST)
Which Fortify product are you interested in? Here is some information on FoD - https://www.microfocus.com/media/brochure/fortify_on_demand_mobile_application_security_testing_brochure.pdf. It isn't an Installation or User Guide, but it does mention that with FoD you can upload your application's binary file for analysis.
Starting on page 139 of the Micro Focus Fortify on Demand User Guide (https://helpcenter.ams.fortify.com/hc/en-us/article_attachments/10765216500243/Fortify_on_Demand_Guide_22.3_EN.pdf#page=139) there are step by step instructions on how to Configure a Mobile Scan for assessment.
If this still doesn't answer your question, my recommendation would be to reach out to FoD Support with your question - https://support.microfocus.com/contact/fortify-on-demand.html or if you are logged into your FoD portal, there is an option for Live Chat in the Help section.