It’s very rare for an artificial lawn to get damaged, they’re made of pretty tough stuff! Damage to a lawn is most likely to occur when people are careless with cigarettes or barbecues and a part of the grass melts, because artificial grass (like most things) is not impervious to extreme heat! Unlike natural grass it will not grow back so the best thing to do is to replace the affected area with a new piece of grass.
This doesn’t have to be difficult job but it is vital the pile is facing in the same direction on both the existing and new pieces of grass to reduce visibility. If you are unsure of how to do this contact Trulawn who will be able to offer some advice as well as source you your new piece of grass.