Unable to import my Minecraft Bedrock Edition mod

I decided to create an addon for Minecraft Bedrock Edition 1.16. So, I added one item (a sandwich) and gave it a texture and recipe. After that, I exported a mcaddon file, sent it to my iPad, and proceeded to import it into Minecraft. However, it told me that it was not a valid zip archive. I tried to separate the behavior pack and the resource pack. When I imported the behavior pack, I got a different error. When I followed the instructions and clicked on the error to see the log, I found that the error list was empty. Can you help me?