The “Post” button has disappeared — it’s now replaced by a “Message” button.

On desktop, you’ll find it at the bottom of the screen:

On your mobile device, you’ll find it at the top right of the screen:

To leave a review on Google, you just need a Google account — you don’t need to have a Gmail address.

You can open a Google account in under 1 minute.

Open an account here.

Note: You can create a Google account using your existing personal email address.
To do this, click the link: Use my current email address instead.