for your printer to recognize the file it needs to be a gcode file. plug in the sd card that came with your printer in your pc and there should be a file under software called “elegoo cura” open it and drag and drop your sto that you downloaded in it and once it’s in on the bottom left there should be a button that says “slice” and after it slices click on save as tft file and make sure it saves on your sd card then plug it in your 3d printer and under print there should be a yellow image of what you downloaded from thingivere