Addiction can sneak up on people, and it’s not always easy to spot when someone truly needs help. If you’re seriously worried, it might be best to suggest professional support.
The problem is that people who are addicted never accept that they are addicted and when someone talks to them about addiction, they immediately run away from that person. This article:
https://gamblershelp.com.au/support-someone/how-to-talk-to-someone-about-their-gambling/has good methods on how to deal with someone who is addicted to gambling. It is not easy to convince an addicted person to go to the hospital and talk to a health professional, especially because in our society there is a mistaken idea that psychologists only treat crazy people.