.net 3.1 and dotnet 6 on ubuntu 22.04 issue [/usr/share/dotnet/host/fxr] does not exist

I've Ubuntu 22.04I've successfully install .net core 3.1using this way

How can I install dotnet Core 3.1 runtime on Ubuntu 22.04?

and it's work perfectlythen I treid to install .net 6

using this way first

but It's did not work for me and nothnig happend with me after trying

dontet --list-sdks 

the version is 3.1 alone

after that I followedthis way from docs

by calling those commands

wget https://dot.net/v1/dotnet-install.sh -O dotnet-install.shchmod +x ./dotnet-install.sh./dotnet-install.sh --version 6.0.421

after that when I'm trying

dotnet --list-sdks

I'm facing this error

Error: [/usr/share/dotnet/host/fxr] does not exist