Install vscode extension from vsix file hosted in the internet. It's useful for distributing private, maybe paid version of your free extension.

extension.ts

import { Uri } from 'vscode'
import * as vscode from 'vscode'
import fetch from 'node-fetch'

export function activate(context: vscode.ExtensionContext) {
    const installPrivateVersionOfExtension = () => {
        const fileBlob = await (
           // Most likely you want to authenticate user to execute that request
           await fetch('https://your.server.com/extension.vsix')
        ).blob()

        const buffer = await fileBlob.arrayBuffer()

        const storagePath = context.storageUri?.fsPath
     
        const fileUri = Uri.file(`${storagePath}/extension.vsix`)

        await vscode.workspace.fs.writeFile(fileUri, Buffer.from(buffer))

        await vscode.commands.executeCommand(
          'workbench.extensions.installExtension',
          fileUri,
        )
    }
}