Questions about Pi Reference Virtualenv

Introduction to the long run. I'm going to make virtualenv When I clicked on the right tooth shape on the setting screen, create virtualenv appeared, but it didn't appear on my pie chams I thought it was a Python version problem, so I kept changing it, erased it, and downloaded it again, but it didn't work I also tried pip installation, but I don't know why create virtualenv doesn't appear on that screen. I'd appreciate your help!