Trouble installing OnionOS (Noob)

My old card got corrupted so I got a new one (Lexar professional 256 GB). I formatted the SD card, downloaded the files onto my computer (Macbook Pro Sonoma 14.4.1), then copied onto the SD card. I put the SD card in my Miyoo Mini+ but only the original screen shows up and there's no installation. Anyone able to help? I am new to this and was using the stock card forever. Many thanks in advance.