Option to add installment to contract/account to increace balance amount same as payment and can be deleted which will reduce balance amount by new amount of the installment deleted, call later added badge to show active call laters

app/Models/Installment.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\SoftDeletes;
+
+class Installment extends Model
+{
+    use HasFactory;
+    use SoftDeletes;
+
+    protected $fillable = [
+        'account_id',
+        'amount',
+        'balance_before',
+        'currency',
+        'reference',
+        'installment_at',
+        'meta',
+        'created_by',
+        'activity_id',
+    ];
+
+    protected function casts(): array
+    {
+        return [
+            'installment_at' => 'datetime',
+            'meta' => 'array',
+            'amount' => 'decimal:4',
+            'balance_before' => 'decimal:4',
+        ];
+    }
+
+    public function account(): BelongsTo
+    {
+        return $this->belongsTo(Account::class);
+    }
+
+    public function activity(): BelongsTo
+    {
+        return $this->belongsTo(Activity::class);
+    }
+}