Can I connect a shared Microsoft mailbox like support@ or info@?

Yes. When adding a Microsoft mailbox, sign in with a Microsoft account that has access to the shared mailbox, then enter the shared address (for example support@yourcompany.com) as the mailbox to synchronise. Deskhero requests the Microsoft permissions "Read & manage shared mailboxes" and "Send email from shared mailboxes" so it can answer customers as, for example, support@ instead of a personal address. Make sure the signed-in account has been granted proper access to the shared mailbox in Microsoft 365 first; the setup screen links to a how-to guide for this.