HI  @Kubus0815 

You may refer to the following article:

How to set up Access Control of TP-Link Omada Router in Standalone and Controller

If none of them meet your requirements, please let us know more information especially the topology and the TPLInk devices  you are using.

Hi Vincent,
here is an overview of my topology.
I have the following networks:

• VLAN 1: Admin LAN
• VLAN 10: Guest Wifi
• VLAN 20: IOT VLAN and WiFi for IoBroker here the home automation is to be realized

All Networks have access to the internet.

At Guest Wifi, Guest Network is activated 

At IOT Guest Network is not activated, that the clients communicate with each other.

IoBroker runs on a RaspberryPi 4, which should be accessible from the AdminLAN, but not vice versa.

 There is no solution to my problem??