Hi,
The supported way to schedule Skype for Business meeting are as following:
1. Outlook
2. Skype for Business web scheduler
Base on my understanding, there is no way to sync Lotus Notes Calendar to O365 calendar and vice versa naturally.
You can post a case on MSDN Skype for Business forum and there are Skype for Business developing experts will help to confirm if it could be achieved or not. Thanks for your understanding.
https://social.msdn.microsoft.com/Forums/en-US/home?category=SfB
Best Regards
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Eason Huang
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