You have been in love for 6 years, which is indeed a long time. You know each other well. Have you ever thought about why your boyfriend doesn't want to get married? Maybe he has some unspeakable secrets.
First of all, you need to find out why your boyfriend doesn't propose and why he doesn't want to get married. These are up to you. You can ask yourself or ask through friends. Anyway, think about it yourself.
It is also very good to hint through gifts. You can give him some meaningful gifts, and then tell your boyfriend, how is our relationship now? He said it's very good! You can say, do you want to continue like this? I want to have a family. Your boyfriend will understand what you mean, I wish you success!
You can also choose to enjoy the world of two people together, and your boyfriend will be happy to do so! You give him a big gift and say to him, I want a child. If your boyfriend wants to marry you, he will say, really! I also want to have a child of my own, and the time of proposal will be advanced. If he still doesn't want to get married, he will hesitate!