Why wouldn't a Read-Host input not get applied later in script?

First off I would like to say I am new to powershell scripting and am experimenting with some ideas. However I keep running into an error and not sure why. Any advice would be much appreciated.  I am doing this in a windows 2016 environment.

$domainname = (Read-Host "Enter name for domain.")


Install-WindowsFeature AD-Domain-Services -IncludeManagementTools

Import-Module ADDSDeployment

Install-ADDSForest -DomainName "$domainmane"
 
Set-TimeZone -Id "Mountain Standard Time"

I get:
Install-ADDSForest : Cannot bind argument to parameter 'DomainName' because it is an empty string.



I have also tried it as:

$domainname = Read-Host "Enter name for domain."

$domain = -domainname $domainname
 
Install-WindowsFeature AD-Domain-Services -IncludeManagementTools

Import-Module ADDSDeployment

Install-WindowsFeature ADDSForest
 
Set-TimeZone -Id "Mountain Standard Time"

However any time I attempt this I receive the following error:
Install-WindowsFeature : A parameter cannot be found that matches parameter name 'DomainName'.
At line:10 char:35
+ Install-WindowsFeature ADDSForest -DomainName "$domainmane"
+                                   ~~~~~~~~~~~
    + CategoryInfo          : InvalidArgument: (:) [Install-WindowsFeature], ParameterBindingException
    + FullyQualifiedErrorId : NamedParameterNotFound,Microsoft.Windows.ServerManager.Commands.AddWindowsFeatureCommand

Thank you in advance!