fill method
Fills the focused field with text, as a platform's autofill does — a
one-time code offered from an SMS — replacing what it held. False when
no field has focus: there is nowhere for it to go.
Implementation
bool fill(String text) {
if (_client == null) return false;
_value = TextEditingValue(
text: text,
selection: TextSelection.collapsed(offset: text.length),
);
TextInput.updateEditingValue(_value);
return true;
}