You can download the configuration guides below:
K2;
https://help.yeastar.com/en/k2/topic/integrate-yeastar-pbx-with-microsoft-teams.html
S-Series PBX;
https://help.yeastar.com/en/s-series/topic/integrate-yeastar-pbx-with-microsoft-teams.html
Cloud PBX;
https://help.yeastar.com/en/cloudpbx/topic/integrate-yeastar-pbx-with-microsoft-teams.html