I want to power an ESP32 with a 3.7V LiPo battery. There's a LED matrix of 64 WS2812 LEDs attached to the ESP32. I learned that I need a buck boost converter to power the microcontroller as it needs a 5V power input. The boost converter delivers that when there is no matrix attached. However if the matrix is attached it only receives about 2.7V. Turning the potentiometer on the boost converter changes nothing in this case. What is the reason for this? I am sorry if this question seems basic to you. I am an beginner with electronics.
Here is a rather hideous scetch of the connections. I hope this is okay:

This is the buck converter I used: https://www.amazon.de/gp/product/B079H3YD8V/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1