Following a question in the comments, here is more information about how we managed to connect the PCB to the power supply (the data being directly sent by bluetooth)

We first started with electromagnetic coils as it's a contactless solution. But we faced some issues: the hall sensor did not get enough power to work properly (the LEDs were ok though).

We ended up going for brushes; which solved the power problem and enabled us to remove some elements from the PCV (AC / DC converter)

ELECTROMAGNETC COILS

We transmit power by the wireless charging module, so for the receiver we use the IC recommended for this module: T3168.

We use the diode in the first part to change AC to high voltage DC, and use IC to control this buck converter to hold the voltage of output.

BRUSHES (hand made...)