If you want to set up your domain with Big Cartel, please follow the following instructions:

1. Sign in to your Dynadot account.
2. Select "My Domains" from the left-side menu bar and click "Manage Domains" in the drop-down.
3. Check the box next to the domain name(s) and select "DNS Settings" from the "Bulk action" drop-down menu.
4. On the new page, select the "Dynadot DNS" option from the drop-down menu.
5. In the "Domain Record (required)" section at the top, select "Forward" as the record type and enter "http://www.yourdomainname.ext" as the "URL".
6. Under the "Subdomain Record (optional)" field, enter "www" as the subdomain, select "CNAME" as the record type and enter "yourbigcartelstore.bigcartel.com" as the "IP Address or Target Host".
7. Scroll down to the bottom of the page and click on the "Save DNS" button to save your changes.
8. Enter your domain with your Big Cartel account.

Please be aware that it might take some time for your changes to propagate.