Payload connector
In the JuniX kit, there is a dedicated IDC‑06MR connector for attaching various spacecraft payloads:

Picture 1. IDC‑06MR connector
It is located to the left of the kit’s camera:

Picture 2. Connector location
For your payload to operate correctly, connect it according to the pinout of this connector:
1) GND;
2) Payload_LED;
3) SCL;
4) SDA;
5) VCC;
6) Резерв.

Picture 3. Connector pinout