No UI-specific configuration is necessary to use the feature in the Loginapp UI. It only needs to be configured in the Loginapp REST API.
Especially, if using the feature in conjunction with dynamic step activation (DSA) the Loginapp UI automatically shows the corresponding checkbox to activate the Remember-Me Token Generating Step (unless using custom step UIs).
The main Remember-Me settings are described in Remember-Me settings and configuration for the Loginapp REST API.