Yes but Apple are much more concerned with security than Samsung are.
If you go and find the Apple developer notes for third party keyboards you'll find an explanation there.
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Here you go, straight from Apple's developer documentation.
There are certain text input objects that your custom keyboard is not eligible to type into. First is any secure text input object. Such an object is defined by its secureTextEntry property being set to YES and is distinguished by presenting typed characters as dots.
When a user taps in a secure text input object, the system temporarily replaces your custom keyboard with the system keyboard. When the user then taps in a nonsecure text input object, your keyboard automatically resumes.
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https://developer.apple.com/library...eral/Conceptual/ExtensibilityPG/Keyboard.html