How to send text/string when key is pressed powershell

Question

I want to make macros using function keys to improve my workflow but the code below doesnt work, i think its quite self explanatory, while the code is running if i press X key, a different text is sent.

$wshell = New-Object -ComObject wscript.shell;  
# choose the key you are after
$key = [System.Windows.Input.Key]::LeftCtrl
$isCtrl = [System.Windows.Input.Keyboard]::IsKeyDown($key)    
while ($true)
{
if ($isCtrl)
{
    $wshell.SendKeys('Thank you for using the service.')
}
}

The code above doesnt work. But if i only use the code below it does send the string as expected.

$wshell = New-Object -ComObject wscript.shell; 
sleep 1
$wshell.SendKeys('Digital service desk')

Answer 1

As stated by Mathias R. Jessen i was not updating the value of $isCtrl inside the loop. I'll now post the code if anyone wants to use it.

$wshell = New-Object -ComObject wscript.shell;



Add-Type -AssemblyName WindowsBase
Add-Type -AssemblyName PresentationCore


while ($true)
{
if ([System.Windows.Input.Keyboard]::IsKeyDown([System.Windows.Input.Key]::F2))
{
sleep 1
$wshell.SendKeys('Message after pressing F2')
} elseif ([System.Windows.Input.Keyboard]::IsKeyDown([System.Windows.Input.Key]::F4)){
sleep 1
$wshell.SendKeys('Message after pressing F4')
}
}