Open the command prompt or terminal window and ‘cd’ to the directory where Experience Builder - Developer Edition was unzipped and proceed to the client folder
Type npm ci and hit enter. This action may take a few minutes to complete
Open up a command prompt (Windows) or terminal window (Mac) and ‘cd’ to the directory where Experience Builder - Developer Edition was unzipped and proceed to the server folder
Type npm ci and hit enter. This action may take a few minutes to complete
Once each of those actions are completed, type in npm start in each command prompt or terminal window
Open up your internet browser and type in https://localhost:3001/. A warning may appear. Click advanced and then continue to localhost (unsafe)
A prompt will appear asking for your organization's URL and the Client ID (App ID) you previously generated
You may get an additional prompt - Request for Permission. Click Allow and you should now have successfully launched Experience Builder
Additional resources:
ArcGIS Experience Builder Developer Edition Installation