Generates a single use sign-in token.

Generates a single use sign-in token for the customer person found for given login or e-mail. Returns 'url' and 'token' which allows to sign-in to customer portal as this person. Token is valid for two minutes and can be used only once. To sign-in to customer portal you should post 'token' provided as the 'accessToken' form param to the 'url' using POST method.Detailed description is available in the Customer API <a href="/api-doc/customer-api/authentication">authentication</a>.