At present, there are no settings to automatically enable recording for all calls within Teams itself or on Microsoft's Phone System: people do want it and its been raised several times on User Voice at https://microsoftteams.uservoice.com/
However, there are third party solutions out there such as Audiocodes SmartTap 360 if you use Direct Routing for Microsoft Teams which may do what you need.
Did you manage to find a solution to your problem? Chris is right, you can use an SBC like AudioCodes to solve the problem, or you can use a CSP that provides a Teams Direct Routing Service if you don't want the cost/headache of managing that SBC yourself.
Call recording is just done upstream of the SBC or on the SBC itself. We do the same and hold the recordings for 5 (Mifid ii) years.