You can access to your server via FTP or CPANEL, then go to app\Plugin\MooApp\webroot\js directory to modify any file.js, to make mooApp apply change please follow those steps :
1. Make sure Node.JS is installed on your server ( we recommend v8.11.1 or above ) then access your server via SSH, go to app\Plugin\MooApp\webroot\js directory and install module dependencies with npm : "npm install".
2. Continue with "npm run build", wait until it gets 100% loading.
3. Go to your site admincp to clear site cache, also please close current app and restart to help clear app's cache on both Android and IOS app .
For developing, because each time you rebuild app, It takes a while for a source to compile and zip, so after pass with step 2, please follow :
2.1 Continue with "npm run watch" ==> it help mooApp watch all mooapp file and auto apply your current change . Go to http://www.yoursite.com/admin/system_settings/view/9, choose Development 1 on System Mode.
2.2 When you finish modifying, via SSH, continue with "npm run build", this is "the last time" build for your app. Then go to http://www.yoursite.com/admin/system_settings/view/9, switch System mode back to Production.
Continue with step 3.