Lotties are a separate component, and require rendering. They only work as stand alone display objects. You cannot put them within a FAB.
Animated FAB can be a visual nuisance. Animation is intended to draw the eye to the point of movement. If you are animating something consistently it can be very frustrating as a user, and result in a lower UI.
i think you didn’t read my post. it is clearly written that the purpose is to let the user know that there is new notification. as there is not extension to show notification count inside the app. it is necessay and is not going to lower the UI experience of user.
Just to clarify and extend what @cian said, according to the guidelines,
A floating action button (FAB) performs the primary, or most common, action on a screen. It appears in front of all screen content, typically as a circular shape with an icon in its center. FABs come in three types: regular, mini, and extended.
In short, it represents an action that’s fixed, meaning it is not intended to change. As Cian pointed out, with animation, you would change it and always draw the users attention to it, until the point it will feel disturbed and annoyed.