This board is from Bigtreetech and went through various hardware revisions; all of them still feature a TFT pin header which is where you can tap the TX and RX needed. The wiring below is made with a 1.2 board, but the same applies for the other revisions as well; if you need the exact schematic for your mainboard version, you can check Bigtreetech's github repository.

The TFT connector is labeled on the board; you can use dupont connectors for the wiring job, no soldering skills needed as long as your ESP comes with pre soldered headers. Note: the TFT connector provides 5V DC, so be sure to provide them on the correct ESP pin.

Board pins voltage	3.3v
Board firmware	Marlin
Board configuration note	Enable second serial port in the marlin configuration file
ESP3D configuration note	Raw serial, no SD