Trying to link one of my domains to a separate landing page instead of home page/normal domain

[Lisagraphics]

Hi,

I have one different product than my normal products that I sell. I made a domain name specifically for this product. I would like to have a separate landing page for this domain name but I'd like it as part of my main website so they continue to explore and find my other products.

I managed to add the second domain name to my shopify but I don't know how to link it specifically to one single page, could someone help me??

I am using testament.

Thank you,

Lisa 🙂