Hello @Lee McArthur , thank you for reaching out. This is not possible as the access-tokens issued for a specific resource for which the request has been sent. Hence access-tokens are always app-specific. From a single app, if you want to access different apps, then from your app you need to send a separate request for each of the other two apps (Office 365 and Business Central) and fetch two separate access-tokens and use them separately to gain access to those apps.
Hope this helps.
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