Adding new Connection

Hey everyone! I've been trying to figure out how to add Pixieset (a photography website to send galleries to clients) on my "connections" tab - Im using a windows laptop with chrome as my browser but also have the app installed. "Connections" allows you to upload your photos from lightroom onto other platforms. When I reach out to customer service I'm being told I need to reach out to Apple Support to figure it out because thats where I purchased my subcription from ???