travel SIM card for Japan

So I’m traveling in Japan, get here and try to set up the eSIM on my iPhone 12, doesn’t work. I go to get a physical tourist SIM card and find out it’s not compatible with my iPhone 12. I want to know why and what to do next to improve my travels here in Japan. If this helps I’ve been trying to do research on Apple Support and tried to unlock my Sim? But it’s locked and says “This device might be restricted to the original carrier and/or have certain capabilities limited” and it’s hard for me to contact any apple support with no data and very limited WiFi. Please help