You can add Sagans to a website you edit in Wix by taking your Sagan's iframe code and pasting it into an Embed element within your Wix editor.
1. To do this, first click the '+' to choose the type of element you wish to add to your webpage
2. Select 'Embed' -- this defaults to 'Custom Embeds: Embed a Widget.' Click the '+' to add this to your page
3. From here, paste the iframe code into the html field:
4. Click 'Apply'