Hello@Gringo1963 ,

Welcome to our community.

According to the translation of Google Translate, your question is that you failed to set up the Archer BE550. If there is any discrepancy, please describe it in English.

Did you get the internet connection information via Mnet? For example, is your internet connection type PPPoE (requires a username and password) or DHCP (automatically obtains a connection)? You'll need to obtain this information from your carrier, usually in the activation email or contract.

What is error message when you tried to set up the router? 

Here is a setup video that provides step-by-step instructions: TP-Link Router Quick Setup.

Hello@Gringo1963 ,

Thanks for getting back to me.

Have you subscribed IPv6 plan? If not, please disable the IPv6. After disabling IPv6, make sure IPv4 is working properly.

There are a few connection types of IPv6 available: Dynamic IP (default), PPPoE, 6to4 tunnel, IPv6 Bridge, DSlite, and V6Plus.

Please contact your ISP if you do not know your IPv6 internet connection type and configuration information.
This FAQ will help you with configuring IPv6 Internet connection: How to set up an IPv6 Internet connection on the TP-Link Wi-Fi Routers.
However, there are a few special cases where ISP only provides prefix-delegation, please refer to How to set up IPv6 service for some specific ISP like BT/Hyperoptic or SKY etc on the wireless router for more details.

Hi @Gringo1963 ,

Here is the post that will help you: Connect TP-Link Archer BE550 to Germany's DS-Lite (Dual Stack Lite) Internet via WAN.