If it is the first engine oil change, you must make it to the right mileage, since what you carry is filming oil. This oil must be changed before normal since it decomposes chemically before the rest.
On the other hand, in a new engine a large amount of metallic chip is generated that goes to the oil filter, if you do not change it in due time, the filter will saturate metal particles causing part of the oil to have to go through the byless by pass valve.
The presence of fine metal particles in grease oil causes the engine components to wear faster (on the one hand it is good, that is the filming, to wear out the small imperfections to achieve a perfect adjustment). But if this effect is excessive, it will cause future oil consumption in the engine. (Filming badly done).
In short, the light turns on for something, and although it fucks a little pay, you run the risk of losing the guarantee if you do not switch to the period of revisions stipulated by Citröen, (the bastards grab a burning nail when there is some fault in guarantee so it is better not to give them a reason for a complaint just in case).
When the guarantee period is over, take the car wherever you want to do maintenance and solve the breakdowns, meanwhile, it is time to endure, go to the house or some concerted workshop (Bosch Car Service) and still, there are workshops that refuse to do maintenance operations to cars in guarantee period.
All the best.