Hi farajeh,
When you have downloaded the Mobile Workdesk app from the app store, it comes with a default cloud account. If you browse this account, you will find a user guide and setup guide in the root folder explaining the different configuration parameters.
The configuration is splitted into three parts, as seen in your screenshot.
In the first one you need to enter a user which can access your Alfresco server and the Alfresco server address (54.235.213.193) and you can give it a description (e.g. AlfrescoWithMWD).
In the Advanced section you have to configure the Alfresco serve port (8099 in your case) , you have to select then the Mobile Workdesk server connector (already done) and as you want to connect against Alfresco the related CMIS service document (/alfresco/cmisatom).
In the Mobile Workdesk Server section you then configure the mobile workdesk server address (54.235.213.193), the mobile workdesk context (/mobileworkdesk) and the related port (8091).
Hope you are able to connect now successfully.
Best regards,
deko