Can someone explain roofing salesperson saying they will help file a claim

We had a guy knock on our door, and he was from a local reputable roofing company. (Good reviews, well known) Our roof is quite old and we didn’t know if it was in good shape. He got up on the roof and we watched him take pictures and then he showed us the hail damage. He then said their company could help us file a claim, meet the adjuster at our house, and help us get the best possible outcome. I don’t understand exactly how this works? Would we call our insurance company, or do they? And he mentioned signing a piece of paper that if we did not get the roof approved would not be valid. I’ve tried searching the posts here, but I’m still not clear on the whole thing.