Install the EpiServer.Templates package globally
dotnet new install EPiServer.Templates
Then install the optional EpiServer CLI tools
dotnet tool install Episerver.Net.CLI -g --add-source https://nuget.optimizely.com/feed/packages.svc/
Once both are installed correctly, find the location of your Optimizely project file in your file system, and run the following command in Powershell (replacing the location of the project at the end of the example below with the location of your project on your local machine)
dotnet-episerver add-admin-user -u AdminUser -p Admin123! -e [email protected] -c EPiServerDB "C:\Users\me\Work\Optimizely\src\MyProject.csproj"
Et voila! Log in to the Optimizely Backend using the username and password combo you added above.