Powershell Script to swap Proxyaddresses and PrincipalName

Question

Been writing script:

foreach ($Username in (Import-Csv -Path "C:\Users\...\nope.csv")) {

    set-aduser $Username.Username -remove @{Proxyaddresses="smtp:[email protected]"}
        Write-Output "remove proxy"
    set-aduser $Username.Username -replace @{userPrincipalName="[email protected]"}
        Write-Output "replace principal"
    set-aduser $Username.Username -add @{Proxyaddresses="smtp:[email protected]"}
        Write-Output "add proxy"

}

the code runs but ends up putting this garbage -> @{Username=###}[email protected] in the attribute Editor.

Any help would be appreciated, been trying different ways for like 8h now.