Hi,
It's probably not the case for everyone on your website but only you because you might be using an email address for your test purchase that PayPal already knows is linked to a PayPal account, or based on the cookies of your browser that PayPal sets for itself to track you.
So try to place an order with another browser and an email address that isn't linked to a paypal account and you will see what users without a PayPal account would see and you'll probably see the "pay without an account" option on the payment page.
Unfortunately, there is nothing you can do in HikaShop to change that as that's how PayPal works.