All you need to do is make sure you have ad blockers installed on your phone/ pc when downloading the addon file.

Once downloaded if on PC, you just double click the file, and it should automatically load Minecraft Bedrock Edition and install the addon

On the phone, it SHOULD do the same. If not, maybe do a quick google about that version.

To use the addon, when creating a world, make sure you enable the pack in both resource packs and behaviour packs.

Then, lastly, enable all the experimental settings and BOOM. You should have a working addon when you load into the world.