vivaldi addon doesnt connect to database

Expected Behavior

I wanted to connect the extension Keepassxc browser with the program Keepassxc, but does not appear (as described in the FAQ) a window in which you can specify the path
Bowser vivaldi as a standalone installaton
Keepass XC installed as a portable version
Integration for this browser has been activated

Current Behavior

no connection between Keepassxc and the extension possible

Possible Solution

extension does not work on a standalone installation

Steps to Reproduce (for bugs)

reproducible at any time

Context

save my passwords in Keepass

Debug Info

KeePassXC - Version 2.3.1
Revision: 2fcaeea

Bibliotheken:

• Qt 5.10.1
• libgcrypt 1.8.2

Betriebssystem: Windows 7 SP 1 (6.1)
CPU-Architektur: x86_64
Kernel: winnt 6.1.7601

Aktivierte Erweiterungen:

• Auto-Type
• Browser Integration
• Legacy Browser Integration (KeePassHTTP)
• SSH Agent
• YubiKey

Enabled extensions:
KeePassXC-Browser Version: 1.1.2
KeePassXC Version: unknown