schedule update is disabled

Hi,

i'm not pretty familiar with the authorizations of power bi.

i created a report with power bi desktop directly connected to a SQL Database

it's an ip in my lan.

when i try to plan the update, it fails

with the message : 

	Scheduled update is disabled because at least one data source has no identifying information. To restart the update, go to the settings page for that data set and enter the credentials for all data sources. Then reactivate the scheduled update.

i am sure of the credentials

Do i have to install a gateway ?

thanks