Welcome to the forum @mkymu8f4
I don’t use mega.nz, but in Mega.nz seems broken just noted a possible cause if your mega account is new. Could you try the “Test connection” button on the Destination screen to see if you’re even getting connected? Looking at your job log’s “BackendStatistics” would show what (if anything) you were actually able to upload.
Or maybe neither of us know where to look in the web UI for the files. Do you have usage stats that went up?