Acuity - synch with multiple Outlook Office 365 accounts

I´m working with e.g. 3 clients. With each client I have a seperate Outlook Account. I have meetings scheduled with every of these clients. The problem is now: The availabilities in my online calendar should be made dependent on these multiple  Exchange/Outlook accounts re their calendars. How can this be realized? For me it looks like I can only connect one Exchange account at a time.

I´m on the growing-Plan...