1. Click the start icon, enter [Windows function] in the search box and open it, and you can see the .NET Framework 3.5 function;
2. Click the plus sign in front of the option, check the two WCF options that appear, click OK, it will display [Searching for the required file], and then wait for the component to download and install;
3. Or right-click the start icon, select [Windows Terminal (Administrator)] in the hidden menu, and start the .NET Framework 3.5 function with the following command:
dism /online /enable-feature /featurename:netfx3 /all
dism /online /enable-feature /featurename:WCF-HTTP-Activation
dism /online /enable-feature /featurename:WCF-NonHTTP-Activation