Service-Public.fr is answering you :

The employer has the power of direction. This means, among other things, that he organizes work in his company and manages the leave authorizations of his employees.

Its role is therefore central and it must comply with conventional rules if they exist on the subject of paid leave and legal rules. These rules concern, for example, the fixing of the period for taking paid leave, the information of employees on the order of departures... The company may also have defined practical rules concerning an application form to be used, deadlines to be respected by the employee, the modalities of response of the employer... The Labor Code does not fix anything on these last points.

The employer has an obligation to take all appropriate measures to enable the employee to exercise effectively his right to leave. Failure by the employer to comply with that general obligation may have the consequence of creating a situation which is disputed and questionable by the employee.

However, an employee who goes on paid leave without notifying his employer, on the ground that the latter had remained passive in the management and organization of leave, is liable to a dismissal measure.

The employer’s failure to manage leave does not, however, mean that the absence of the employee who left without warning was authorized. Dismissal of the employee concerned is then a possibility.

In a similar situation, the Court of Cassation held this in a judgment of 13 December 2023.