If you are on version 4.20.0 :
Open Sideloadly, click on "Advanced Options", mark "change app version" and write "4.21.1", now click start and wait the upload.
Open the app and automatically it will download all the necessary.
Open Sideloadly, click on "Advanced Options", mark "change app version" and write "4.21.1", now click start and wait the upload.
Open the app and automatically it will download all the necessary.