This resource pack uses cape file system from Minecraft Java 

You will be able to choose 2 types of animation in the resource pack settings for your cape, that of Minecraft Bedrock by default and a more realistic animation (requires restarting the game if this parameter is changed)

This resource pack uses the Minecraft Java capes files for more compatibility with existing capes and for better customization of capes and elytras (Migrator cape is used as the default cape)

Installation of the resource pack without modifying the cape:
You can either download the .mcpack file, launch it to import the resource pack into Minecraft, or download the .zip file and place it in the resource pack folder.

To customize the cape:
If you downloaded the .mcpack, you will need to go to the "resourcepack" of Minecraft Bedrock folder then to the "Customcape" folder
Otherwise you have downloaded the .zip, you will have to unzip it and go to the folder (once the operation is complete, you will need to move the extracted folder into the Minecraft Bedrock "resourcepack" folder)
Once inside, you will have to go to "textures" then "entity", you will find the file of the Migrator cape, you can take the cape and you can replace the file or modify the base cape as you wish, there is an online software Minecraft Capes Editor, then you can replace the base file keeping the same file name (custom.png)

And voila, you have your cape 🙂 (You can change the cape as many times as you want)