Need to enable RStudio Keymap extension, c.f. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE--jhTjOK4vQ8.html github.com/posit-dev/positron/wiki/Keyboard-Shortcuts#rstudio-keymap
You will have to go through the command palette. Open it by pressing CNTRL + SHIFT + P (Windows) or CMD + SHIFT + P (macOS). Then, type: Quarto: Create Project From there, you have the option of default, website, blog, book, or manuscript.