Anonymous function never returns null so it can be removed from the return type.

Anonymous function should return string|null but returns int|string.

Parameter #1 $options of method Laravel\Nova\Fields\Select::options() expects (callable(): (class-string<BackedEnum>|iterable<int|string, array{label: string, group?: string}|string|Stringable>))|class-string<BackedEnum>|iterable<int|string, array{label: string, group?: string}|string|Stringable>, array given.

Parameter #1 $options of method Laravel\Nova\Fields\BooleanGroup::options() expects (callable(): iterable)|iterable, mixed given.

Parameter #1 $options of method Laravel\Nova\Fields\BooleanGroup::options() expects (callable(): iterable)|iterable, mixed given.

Parameter #2 $query (Illuminate\Database\Eloquent\Builder<App\Models\DuesPackage>) of method App\Nova\DuesPackage::relatableQuery() should be contravariant with parameter $query (Illuminate\Contracts\Database\Eloquent\Builder) of method Laravel\Nova\Resource<Illuminate\Database\Eloquent\Model>::relatableQuery()

Parameter #2 $validator (Illuminate\Validation\Validator) of method App\Nova\DuesPackage::afterValidation() should be contravariant with parameter $validator (Illuminate\Contracts\Validation\Validator) of method Laravel\Nova\Resource<Illuminate\Database\Eloquent\Model>::afterValidation()

Parameter #2 $query (Illuminate\Database\Eloquent\Builder<App\Models\Attendance>) of method App\Nova\Filters\Attendable::apply() should be contravariant with parameter $query (Illuminate\Contracts\Database\Eloquent\Builder) of method Laravel\Nova\Contracts\Filter::apply()

Parameter #2 $query (Illuminate\Database\Eloquent\Builder<App\Models\Attendance>) of method App\Nova\Filters\Attendable::apply() should be contravariant with parameter $query (Illuminate\Contracts\Database\Eloquent\Builder) of method Laravel\Nova\Filters\Filter::apply()

Parameter #2 $query (Illuminate\Database\Eloquent\Builder) of method App\Nova\Filters\DateFrom::apply() should be contravariant with parameter $query (Illuminate\Contracts\Database\Eloquent\Builder) of method Laravel\Nova\Contracts\Filter::apply()