1- Open Affinity Designer.
2- Open the file you need shaped text in.
3- Select the shape tool you would like to create your text in from the left toolbar, and draw your shape.
4- In the left toolbar,select the artistic text tool and click on the little grey triangle. This will bring up a drop down box that has the frame text tool. Select it.
5- With the shape selected, position the text frame cursor over your shape. A small pentagon will appear. Click when this happens. Your shape will become a framed text box.
6- Another way to create a shape text box is to select your shape then go to Layers > convert to text frame. This will create your shape to a text box.
7- You can now add your text to the shape and the text will only stay inside the confines of that shape.