Fonts make the design. There is a wide choice of different types, but unfortunately not everyone has the same fonts available.
It is therefore advisable to convert the fonts into outlines in your design. This way you avoid error messages on missing fonts and you can be sure that they are always displayed correctly.

How do you convert texts into outlines?

Open your design in InDesign or Illustrator (2021). Select the texts and click on Type → Create Outlines in the menu bar at the top.

In the texts below, you will see the letters selected separately for the text that has been converted to outlines. Here you can no longer edit the text. This is still possible with the text without outlines.