No. Resigning is the employee's right and takes effect without approval. What depends on the employer is waiving the notice period: CLT article 487 requires an employee who resigns to give 30 days of notice, and the employer may agree in writing to waive it or insist on it. Without a waiver, an employee who does not serve the notice may have the pay for that period deducted (art. 487, paragraph 2). That is why the waiver version also provides for working the 30 days if the company refuses.