Step 1:

Go to Wix website editor - Log in to your Wix account and choose the website where you'd like to add the widget. Click Edit Site:

Step 2:

Add HTML block - Click Plus icon (1), go to Embed section (2) and select Embed a Widget (3) on Custom Embeds tab:

Step 3:

Paste the installation code - Click Enter Code (1), paste your installation code (2) and press Update (3): 

Step 4:

Adjust the widget's size and position - Drag the widget to the right page area and stretch it to get the size you need. Keep stretching until scroll bars are gone and all the required information fits into the block: 

Step 5:

Adjust the mobile appearance and Publish - Switch to the mobile editor by clicking on Mobile icon (1), adjust your widget's size by stretching it (2), and press Publish (3):