Use this below code:Simple just load the upload object with the file which you placed in the local system.
Like load the object with you local file path.
WebUI.uploadFile(findTestObject(‘ASACoverObjs/ChooseDocFileBtnObj’), “F:\\AutomationProjects\\BeautyBookingWebSite\\BeautyBookingWebsiteAutomationProject21042017\\Data Files\\TestDataFiles\\Test Data Doc file.docx”)