How can we show the loyalty points that a customer has left?

There are two ways to achieve your requirement, please check below:

A) Add the widget for this  – 

1)Go to the Appearance -> Widget -> You’ll find a widget naming “Points And Reward”

2) Drag this to your sidebar along with the Title and other Details for that widget.

It will show your Current Points.

B) If you want to use the Shortcode Method –

1) Please place the shortcode [MYCURRENTPOINT] at your checkout page then update.

2) You may change the Text for this Shortcode, Please go to the Other Setting Tab and set your required text for [MYCURRENTPOINT] shortcode.