PHP extension error

Using Neos & Flow
1

When I accessed http://dev.tutorial.local/index.php, The following error message was displayed.
Flow requires the PHP extension “mbstring” (Error #1207148809)
I use ubuntu in windows 10 and also use apache web server.

2

You are missing the PHP extension “mbstring”. Depending on your local setup, you need to install or enable it

3

Thank you for your reply.
I will try.