playback

What do you mean by "trouble"? If you don't know how to do something, look in the Handbook. If you have read the Handbook and followed the advice there but are still having problems then post again and give as much information as possible.

I don't know what ireal is or how it can interact with MuseScore

If you are using a mobile device and the app for mobile devices, that is supported strictly over at musescore.com. If so, read How and where to ask for support

For additional information, see the following:
https://musescore.org/en/faq#faq-314712
https://musescore.org/en/faq#faq-20657
https://musescore.org/en/faq#faq-359393
https://musescore.org/en/node/314712
https://musescore.com/user/32018844/subscription