Redirect wordpress subdomain to squarespace main domain

I previously had my website on Wordpress and it was divided into subdomains for a couple of niche markets. However, I've built my site on squarespace as one site containing all niches. How can I redirect subdomain traffic to my main site on siteground? I've tried URL mapping but it's not working and I believe it's due to the subdomain. I tried it with and without the full web address before the "/"

Have you found a solution yet?