Just figured it out!
Referencing this post: https://ww.wp.xz.cn/support/topic/http-406-remote-site-not-accessible?replies=10
It appears that you can go into the function function dbs_post($url, $action, $params) within the functions.php file of the plugin, and create a $header variable, which you can then add to the CURL request, exactly like rearley did in the above referenced post.
The only difference needed for me was that I had to add the following to the beginning ofn the $header array:
$header[0] = "Authorization: Basic *****************";
Where “*******” represents an authorization key. I was able to find the authorization key for my site by using Dev Tools->Network Panel to read the HTTP request that my browser sent to my remote site after I entered the username and password in the dialog box.
