Accessing to different MySQL tables for Looker Studio Report

[RMK]

Hi,

I am discovering Looker Studio.

I am trying to create my first data report.

I want to use data coming from a MySQL database running under my GCP environment.

I could select a table in the list of my tables, I see the columns and I was able to create a basic report from the data of one single table.

But When I want to create more complex reports with data coming from different tables,  I am not able to create a joint connection between tables.

When I go to the menu "Combine / blend data" I guess I should see the different tables of my database, select two of then and configure on which column they are joined.

But I do not see the list of tables, when I click on "Join a table" I just see a list of data sources, not tables (see on photo attached).

Thank you for your help.

Guillaume