change the validation

app/Models/RoadPatrol.php

@@ -6,6 +6,7 @@ use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\HasMany;
 use Illuminate\Database\Eloquent\Relations\MorphToMany;
+use Illuminate\Database\Eloquent\Casts\Attribute;
 
 class RoadPatrol extends Model
 {
@@ -13,6 +14,13 @@ class RoadPatrol extends Model
 
     protected $guarded = ['id'];
 
+    protected function stopPoints(): Attribute
+    {
+        return Attribute::make(
+            get: fn ($value) => $value ? json_decode($value) : null,
+        );
+    }
+
     public function observedItems(): HasMany
     {
         return $this->hasMany(ObservedItem::class);