This is because your domain name is currently pointing to Bodis, a domain parking service we use for unused domains. Your site shouldn’t point to it though, but it’s a known bug that new accounts sometimes are not set up correctly.
To fix this, you can go into the control panel and go to Addon Domains. From there, you can remove the domain from your account and add it again. This will ensure that the correct settings are generated on our end.
Two things to note if you do this: the updated settings include a DNS change, which can take up to 72 hours to be visible everywhere (more info). And recreating the domain will result from the domain being linked to the main htdocs folder to a separate domain folder sudokusystem.com/htdocs, so you’ll need.
Is this a new site or are you migrating an existing one? If it’s the former, you shouldn’t have to touch the config file. You can install WordPress with Softaculous, in which case you don’t have to touch any files, and if you prefer manual installation you’d generate the config file through the installation wizard.
If you are migrating an existing site, please check the details in the MySQL Databases in the control panel for what to use, and use the values shown there.
And don’t use backup/migration plugins. They tend to break. Just follow the official process from both us and WordPress and just copy the files and database contents: How to migrate your website to InfinityFree