Nosemasks like those usually need warmth (meaning sunlight outside) for the material to stretch slightly for the tabs to reach the areas where they go in, especially on the first install and the mask is new. Obvious thing is make sure the part is made for your specific model car.
As a test, remove it and just install 1 side and leave the other side loose. Can you now insert the tabs into where they go between the headlight and fender gap? If you can the part will go on wait till a nice sunny day and leave the car and mask folded out outside to bake for like 15-20mins then try to install it, the heat will help the fabric stretch a bit while you install and you will find the tabs will be able to reach the areas they are suppose to go into. Once you get the part on leave it outside for a little bit longer for it to "form" around all the curves and contours of the car and next time it will be a lot easier to install sunlight or no.