Is it possible to create a password protected page in the e-shop, to give access only to a limited number of clients?

Hi, I'm Paul, founder of SF Digital, a specialist company building the features that Squarespace didn't include. 
I am a Squarespace Developer and Squarespace Circle Leader with a strong reputation on the Squarespace Forum. I'm trusted by thousands of Squarespace users worldwide, including designers, freelancers, business owners and agencies. My extensions add capabilities to Squarespace websites around the globe. They include the Enquiry Form Extension, Date Picker Extension and Age Verification Extension. Need a custom Squarespace extension? Tell me about the functionality you need. Note that some links in my posts may be affiliate links.