How can I send a call report as an email?

Open a call report in its detail view. Within the menu (the ellipsis icon ...) use the option Send as Email.

Outlook opens a draft email that has a link to the call report, some default content, a reference to the meeting, and attendees of the meeting. The To field shows email IDs of contacts and assignees of the call report. You can change the content, add more people as recipients, or copy people to the email. Send out the email when ready.