Final changes

app/Models/Modification.php

@@ -3,6 +3,8 @@
 namespace App\Models;
 
 use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
+use Illuminate\Database\Eloquent\Relations\HasMany;
 
 /**
  * @property int $id
@@ -23,4 +25,9 @@ use Illuminate\Database\Eloquent\Model;
 class Modification extends Model
 {
     protected $fillable = [ 'name', 'slug' ];
+
+    public function entries(): BelongsToMany
+    {
+        return $this->belongsToMany(Entry::class, 'entry_modifications');
+    }
 }