The Nimble integration must be enabled.
In the widget settings "Ask the visitor's phone number or email address" must be enabled.
In order to match the contacts, your Nimble contact must have the same email address or phone number entered by the visitor. In Nimble, your contacts' phone number must be in international format with the country code. (example for USA: 13477780714 / example for France: 33150505050)
If the Nimble integration is enabled, the Ottspott Phone Widget will match your website visitor with your Nimble contact record.
If you didn't yet activate the Ottspott/Nimble integration, please check this section.
Slack notification with Nimble contact matching:
The Slack notification displays the Nimble contact name (example here "Sheldon Cooper"). If you click on the contact name, the Nimble tab will automatically open with the profile contact info.
The screenshot below shows the Slack notification details:
The Nimble screenshot below shows the contact name display: