Write to support@rpmrpmrpm.com. A person reads it.
Uploads resume on their own. If one stays stuck, check the storage figure in the app: an account at its 100 GB limit refuses new files rather than silently dropping them.
The browser window has to be allowed to return to the app. If it closed too early, start the sign-in again โ nothing is left behind by an abandoned attempt.
Everything the app guessed can be corrected in the app, and your correction wins over anything fetched afterwards.