Heres the answer after i couldnt refresh dashboard in powerbi service of microsft

For custom connectors to work with the on-premises data gateway, they need to implement a “TestConnection” section in the custom connector’s code. This section isn't required when you use custom connectors with Power BI Desktop. For this reason, you can have a connector that works with Power BI Desktop, but not with the gateway. For more information on how to implement a TestConnection section, see this documentation.