For organizations that need call recording for compliance purposes, admins can set via policy. To see how this works for calling and meetings, please see https://docs.microsoft.com/MicrosoftTeams/teams-recording-policy.
1:1 convenience recording is currently on the teams backlog. We will share an updated here as soon as it is available.
An error occurred while saving the commentScott Moore commented
If you would like a work-around that lets you record calls today, then you can choose the "Show Participants" while you're in a Teams Call...add another participant to the call, such as your cell phone which you can answer and mute (or a dummy teams user that you can answer for), and the recording button with be enabled. After your call is finished, the recording with show in the chat area under the Recent group (saved to Stream)