Can¨t change permalink

Whenever I write a post, the permalink is automatically set to “https://www.oslospraytan/shoppingcart”, which means it takes over as the site for my WP Marketplace shopping cart. When attempting to edit the permalink it doest allow me. As a result of this, I have stopped creating posts and instead creating pages, but this isnt ideal as it means I cannot create any tags.
Can you please assist??