Hi Gaëtan Devos,
Do you mean you want to automatically record Teams meeting?
At present, there are no settings to automatically enable recording for all calls within Teams itself or on Microsoft's Phone System.
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.
If it cannot meet your requirements, we recommend you give a feedback to https://microsoftteams.uservoice.com/forums/555103-public/suggestions/35515465-automatic-recording-meetings.
Microsoft will always focus on customer’s feedback and experience. Some new features would be added to the services based on customers' feedback in the future, and your good ideas will be very helpful for them to improve the service.
Your time, understanding and cooperation will be highly appreciated.