Ash here from the Shopify team. Thank you for posting your question in the Shopify Community!
It sounds like you've enabled the password page for your online store, but are unable to see the option to enter the store using it. I'm happy to take a closer look into this with you and figure out what's going on. Could you please reply back to this post with a link to your store? I'll see if I can locate the option to use the storefront password on my end, and if not- we can dig a bit deeper together. Looking forward to hearing back!