Manage relationships greyed out when connecting to datasets in Datamart

[Jessie666]

I want to build relationships of the dataset that is in the datamart. The connection shows "connected live to the power BI dataset". However, the manage relationships button is greyed out. How can I build relationships for the datasets in powerbi datamart?

[Jessie666]

This screenshot is the data flow in powerbi. It will auto-refresh regularly. 

[Jessie666]

[andhiii079845]

Which datasource do you use in the underlaying source of the datamart? Perhaps its is a live connection? 

[Jessie666]

Hi, it is a live connection. This data source is connected to SSMS to the datamart. In this case, how can I still create relationships?

[andhiii079845]

You have to create in SSMS. I think. please check the feature of a live connection.