How to create a keystore file?

I want to use bepswap, but in order to connect it with binance chain wallet, I need the keystore file. There is a function to export the keystore file, but that function is ONLY available to people with a binance.com account. I really want to invest in Rune but I’m a hamburger American, how can I export my keystore file? I’m using Binance Chain Wallet.