Search for the PlatformIO plug-in in the VSCODE extension and install it.
After the installation is complete and the reload is completed, there will be a small house icon in the lower left corner. Click to display the Platformio IDE home page
Go to file - > Open folder - > Select the LilyGO-T-Keybord folder and click the (√) symbol in the lower left corner to compile (→) for upload.