I want to change this text to my custom text in all form builder validators in the app.
You can use this package form_builder_validators which you can pass your custom error text like this
FormBuilderValidators.required(errorText: "hello world")
here an example
Padding(
padding: const EdgeInsets.all(8.0),
child: FormBuilder(
key: _formKey,
autovalidateMode: AutovalidateMode.always,
child: FormBuilderTextField(
name: 'email',
decoration: const InputDecoration(labelText: 'Email'),
validator: FormBuilderValidators.required(errorText: "hello world"),
),
),
),