Go to app’s Settings > Autofill and select Autofill in apps.
Select SafeInCloud as Autofill service.
Tip: You can also access this setting via the phone’s Settings app.
Start an app that requires the authentication. Tap the login or password input field. You will see a popup with Unlock SafeInCloud item. Select it and unlock SafeInCloud.
Tip: You can adjust how often to require the unlock via SafeInCloud Settings > Autofill > Authentication.
Then you will see the autofill suggestions in the popup. If there are no suggestions, select Search item and locate a required item in SafeInCloud.
Then SafeInCloud will autofill the selected item into the login and password fields.
Tip: You can also use this mechanism in some browsers (e.g. Firefox, Opera, DuckDuckGo…), but not in Chrome. For the autofill Chrome see this article: Autofill in Chrome
If there is no popup with the autofill suggestion, tap and hold an input field and select Autofill from the context menu.
Tip: You can use this mechanism in many apps, but not all. A developer of an app should implement support of the standard Autofill API first.
If some card does not appear as an autofill suggestion, check that it has the Use for Autofill checkbox.
For some apps you might need to Add another field of the Application type to a card. Then select a related app by pressing the Droid icon next to the field.
Also press the Autofill (a magic wand) icon on the toolbar and make sure that the card’s fields have correct autofill attributes: User name, Password, and Website.