At first install the extension from chrome webstore

After installing the extension, pin the extension from top-right buttons in chrome then you will see the Pockets icon of your Chrome browser. Click on the icon to open the extension popup.

A setup required screen will appear. Go to the settings page by clicking on the settings button.
As well as visit Silo App to create an account and get your API key.

In the silo app, you need to create a project first then go to the API keys section from top menu and create an API key for the project you created.
Copy the API key and paste it into the extension settings page API key field, and project slug/id in the project field.

After filling the fields, test the connection if you want, then click on the save button. Now you are ready to use the extension.
Go back to the popup and start saving links by clicking on the save button.