Select "Manage" → "Extend" and then click "Install new module
Select the location of the onWebChat module and upload it. Then click "Install" button
Search for onWebChat module, select it and click "Install"
After module installation click on the link "Add onWebChat widget on your drupal website" and then click "Configure" button
Paste your Chat Id and then click "Save Configuration".
If you don't have an onWebChat Chat Id, please create an account here.
Congratulations! Your live chat widget is now available on your website.