Many pre-built PCs have PSUs without visible labels (hidden under shroud). Try these steps:
Several third-party software tools can provide detailed information about your system's hardware, including the PSU wattage. Here are a few popular options: check psu wattage windows 11
If you cannot open your case and cannot find your model specifications online, you can estimate the wattage you need to confirm if your current PSU is up to the task. Many pre-built PCs have PSUs without visible labels