To insert the view in browser link, first select the text you want to link to the web view. Then click on "Insert" in the text editing toolbar and then choose from the dropdown menu the option "View in browser".

Do the same to insert the unsubscribe link. Select the text you want, then click on "Insert" in the text editing toolbar. Choose the parameter "Unsubscribe" from the dropdown menu.

You can also add the unsubscribe link to a button. For that, write the parameter {{subscription}} as the link for the button. To do that, first click on the button settings icon (1), then write {{subscription}} to the URL field (2) and then click OK (3).