Regarding your code in the question.
Your team should work as is. In fact, you are already calling Get-ChildItem. If you check Get-Alias, you will see what I'm trying to tell you.
PS C:\users\Cameron\Downloads> Get-Alias dir
CommandType Name ModuleName
----------- ---- ----------
Alias dir -> Get-ChildItem
You translate the code into
Get-ChildItem -Recurse "C:\temp" | Select Fullname
, , , , . , ? PowerShell? ( Get-Host).
, , . , - ?
, , , Get-ChildItem
Dir -Recurse c:\path\ | Get-Childitem
C:\TEMP\TEST
│ File1.txt
│ File2.txt
│
└───Folder1
File3.txt
, .
PS C:\users\Cameron\Downloads> Dir -Recurse c:\temp\test | Select Fullname
FullName
--------
C:\temp\test\Folder1
C:\temp\test\File1.txt
C:\temp\test\File2.txt
C:\temp\test\Folder1\File3.txt
PS C:\users\Cameron\Downloads> Dir -Recurse c:\temp\test | Get-Childitem | Select Fullname
FullName
--------
C:\temp\test\Folder1\File3.txt
C:\temp\test\File1.txt
C:\temp\test\File2.txt
C:\temp\test\Folder1\File3.txt
File3.txt, .