Chat Button and Text Chat Link Positioning
With Magento module you have two options - either to add a chat button or link to the position available with your Magento theme for the module or add your button or link to some fixed position on the browser window:
1.If you would like to proceed with the first option and add the chat button to selected for a module position, you'd need to select the position from the drop down list. If the position is not available on the page with the theme, the chat button will not appear.
Position available with Magento Module
2.The second options lets you have your chat button displayed at any fixed position on the browser window. This is convenient if you would like it to have a vertical button, for example:
Fixed position on the browser window
For selecting the position, you need to enter vertical and horizontal values in pixels or percent.