Then you already have everything you need — it's in your messages.
Tap the link in it — that's your personal booking page. It opens on a welcome message from your studio, and you can ask for a time right there.
Ask your studio to send it again — it takes them one tap. Your link is personal to you, so we can't recreate it here.
Prefer an app? Install Schedalize, then tap the link in your text again — it opens right in the app, same conversation.