What is wrong? I have created the subdomains with my host (webgo),
You don’t actually do this. Multisite subdomains are virtual, automatically managed by WordPress, and you should not manually create the subdomains in your hosting control panel (other than defining the DNS host entry).
Please remove the subdomains you created in your hosting control panel, and follow the instructions below to create a Multisite network.
routerlogin.ltd
pikashow.ltd
