hope this fix your issue The folder structure of your SAP UI5 app is very important during deployment. Ideally you should have your webapp folder and your dist folder as the only folders in the root directory of the app. (It's okay if you do not have a dist folder). Your neo-app.json file should also have a line like "welcomeFile":"webapp/index.html", pointing to your index.html or the root file of your application.
seems to work fine I placed all my binaries (PNG images in my case) into a separate folder /png under webapp folder in Web IDE and in controller onInit event I calculate the path like this ("hcm.myleaverequest.ESSLeaveReqExt" is my app id):