MDL not possible and other strong issues!

Hi!
No way to install MuseScoreDrumline - reason:
The online instruction tells me:
"Once you have installed MuseScore 2.3, go to the Resource Manager (Help / Resource Manager)."
That's fine. But I have installed 2.32 already and I cannot find Resource Manager in Help or Sub-Menue.
Additionally I canno't find any other solution to install the MDL extension. Why?

Another point - and here I'm quite angry about it! Monthly I'm paying a user fee to MuseScore to use your cloud services an to synchronize my partitures with my smartphone app. But the MuseScore is getting worse and worse with every update. Sometimes I have to log in several time to see my partitures, sometime the app failed, sometime no way to play my partitures, no way to scroll within the partitures, and the worst issue of all: even I paid already for the app and my monthly fees, the app tells me to Go Pro - therefore no Pro functions available. This makes me more than angry and I'm thinking about to cancel my membership!

Please help me!
Thank you very much in advance,
Alexander