mail swipe options

On my iPhone I primarily use Gmail app to read and manage my two Gmail
accounts. Sometimes I use the Apple Mail app.

On the Gmail app I’ve set up the swipe left option to delete a message.
However on the Apple Mail app there is no Delete option for swiping left or
right. There’s also no Delete button on the toolbar! I must click the three
little dots to finally find the Trash message option.

Why is this and how do I expand the swipe options to allow a delete action?