Talk to my bf to have sex more

So me and my bf have been together 3 years we used to have sex multiple times a week 3 to 4 and now it’s maybe once a week and or once every few weeks we have a home together and not kids just a dog so nothing stressful I know he works outside a lot especially in summer for his job but I need at least 2 to 3 times a week I’ve brought it up to him multiple times and he says he agrees to do it more but doesn’t try and or do anything to want to do it. I know work is stressful and he’s tried a lot when coming home but shouldn’t be a excuse idk how to say it anymore to him