@thorn thanks so you basically are suggesting to take away the Pi in the meantime, connect by wire the ESP32 to the strip to config WLED and then go back to my previous setup.
However I had the ESP32 powered through a micro USB cable with the two wires connected to the (5V 40A) power supply and the LED strip connected to the same power supply.
Then the ESP32 D15 pin connected to the green LED strip data line throug a jumper wire.
I just finished doing the exact same thing but mine is wired different. PI3 is running hyperion and has an USB HDMI capture card from my receiver. NodeMCU has WLED installed and connected to my network. Projector screen has LED strip connected to power supply using the 2 cables coming from the strip. Normally, LED strips some with the 3-pin connector plus 2 more power cables. So in order to power the strip, you wire those two loose cables to the power supply, leaving the 3 cables with the plug. Those 3 cables are wired into the NodeMCU. The power supply powers the strip and the MCU. Back to the PI, in Hyperion, you configure the LED Hardware to use UDPRAW as the controller type, fill in your LED count and RGB order, followed by the IP of the WLED instance and finally using port 19446. Save config. If you connect to the IP of the WLED, you’ll get a message stating that it is receiving live data from Hyperion. That should be it