upgrade to filament v4

app/Filament/Resources/Clients/RelationManagers/ExpensesRelationManager.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace App\Filament\Resources\ClientResource\RelationManagers;
+
+use App\Filament\Resources\ExpenseResource;
+use App\Models\Expense;
+use Filament\Forms\Form;
+use Filament\Resources\RelationManagers\RelationManager;
+use Filament\Tables;
+use Filament\Tables\Columns\TextColumn;
+use Filament\Tables\Table;
+
+class ExpensesRelationManager extends RelationManager
+{
+    protected static string $relationship = 'expenses';
+
+    protected static ?string $title = 'Expenses';
+
+    public function form(Form $form): Form
+    {
+        return $form
+            ->schema([]);
+    }
+
+    public function table(Table $table): Table
+    {
+        return ExpenseResource::table($table)->headerActions([
+            Tables\Actions\Action::make('New Expense')->action('openCreateForm'),
+        ]);
+    }
+
+    public function openCreateForm()
+    {
+        return redirect()->route('filament.admin.resources.expenses.create', ['client_id' => $this->getOwnerRecord()->id]);
+    }
+}