How do i connect 2 domains to my website?

My site is connected to a .nl domain which is managed inside squarespace domains. I have a .no domain from a provider called one.com, and I want to connect the .no domain to my website.

When customers enters the site on the norwegian language, i also want to have .no domain display instead of the NL.

I´ve tried connecting the domain via DNS settings, but nothing works.