that is, the script should provide the license2.txt and then the powershell should filter the words name | Key material but I can't execute the command powershell
(Get-content .\Licence2.txt) -replace "(</name|</keyMaterial )", "" >Licence.txt
In order to execute a Windows PowerShell command from cmd.exe / a batch file, you need to call the former's CLI, powershell.exe, documented in about_PowerShell.exe (for PowerShell (Core) v6+, it is pwsh.exe - see about_Pwsh).
The general approach to passing arbitrary PowerShell commands to powershell.exe from cmd.exe is:
Enclose the command(s) in "..." overall, and pass that string to the -Command (-c) parameter (which is powershell.exe's implied parameter, though note that pwsh.exe now defaults to -File (-f) instead, so it's better to be explicit).
Escape any " characters that are part of the command(s) as \"[1], or, if feasible, avoid embedded " quoting altogether and use embedded '...' quoting (verbatim PowerShell strings) that doesn't require escaping inside "..." at all.
Therefore, in your case:
powershell -c "(Get-Content .\Licence2.txt) -replace '</name|</keyMaterial ' > Licence.txt"
Note that I've omitted the unnecessary (...) from the regex passed to the -replace operator, as well as the unnecessary "" replacement operand (replacing what matched with the empty string is the default).
Additionally, it is good practice to precede the -Command (-c) or -File (-f) parameter with -NoProfile, so as to suppress the unnecessary and potentially side-effect-inducing loading of the profile files, which are primarily intended for interactive sessions.
[1] If this fails (which happens if the characters between the \" delimiters contain cmd.exe metacharacters such as & or |), use "^"" with powershell.exe, and "" with pwsh.exe.