If this happens,
there might be several causes with different solutions:

Dependencies

If your dependencies use bindings,
they might need updating to silence the warnings.
Your builds should be unaffected except for
the verbose warnings.
You can ignore the warnings for now
(maybe reach out to your dependency’s
developers to convince them to update).

Your code

If the problem refers to your own code,
you can update it by running dart fix --apply.
This should resolve all the warnings.

If you need your code to support both
Flutter 3 and earlier versions
(maybe because your code is a library),
then you can wrap calls to binding.instance
with calls to a method such as the following:

/// This allows a value of type T or T?

/// to be treated as a value of type T?.

///

/// We use this so that APIs that have become