src/Repositories/Repository.php
public function onlyFillablePivot($pivotRelation, $data)
    {
        $fillable = $this->getPivotFields($pivotRelation, 'pivotColumns');
        
        return array_only($data, $fillable);
    }
public function onlyFillablePivot($pivotRelation, $data)
    {
        $fillable = $this->getPivotFields($pivotRelation, 'pivotColumns');
        
        return array_only($data, $fillable);
    }
Get only fields fillable from Pivot Relation

@return array