How to display a thermometer icon on SSD1306 with ESP32 coded with micropython

I’m an old(74) newbie of micropython and I’m trying to display small icons such a thermometer for temp and a droplet for humidity on a SSD1306 OLED since I’m using a BME280 connected to an ESP32 coded with micropython.
I discovered on the web your online image converter and I tried it thus obtaining a C array ( if this the correct term, English is not my mother-tongue) of the source image (a small 1Kb monochrome icon of a thermometer in png format).
Then I tried to follow the process described by one of the LVGLforumers( kdschlosser ) at this link Image converter for MicroPython but - due to my very modest competence - I got stuck.
I downloaded from the site the that I uploaded on my ESP32 (I’m using Thonny since I am a beginner), then I looked for image_loader that is requested to run the code but I was not able to find it.
Besides this problem, I have also this other doubt. I uploaded on my ESP32 the converted file (C array) so that the uPy code can find the file, this way probably avoiding problems with path errors. .
I’m referring to the code line img.set_src(image_loader.thermometer-1829) where thermometer-1829 is my converted image, but I really do not know if this is correct.
Thanks for your help and apologies for the maybe silly questions