The advice shared about Restore Purchase makes sense if you subscribed through your mobile app. However, it seems like you have a desktop subscription and in this case Restore Purchase will not help.
Please try the other advice about signing out and back into your mobile app, and please be sure to sign in with the same Email ID you used to sign into your Lightroom desktop app. My guess is that you are not signed into the correct account on your mobile app.
If you still need help, please contact Adobe Support directly. Visit https://helpx.adobe.com/contact.html, sign in, and then select the chat option.