A phonetic symbol is necessary

Commercially available computers have the standard fonts already installed in their operating system (Windows, MacIntosh, Unix, Linux). You can find it e.g. under Windows under "Control Panel" - "Fonts" or "Fonts". Phonetic transcription characters are not part of the standard, but have to be integrated into the system at a later date. By the way, you can check in the following way whether phonetic characters can be integrated in your writing program, e.g. Word: Go to "Insert" - "Symbols" - "Additional symbols" and a scrollable overview of all available "special characters" opens. Pay attention to the form field at the top right, there appears "IPA extensions" in a certain position.

The phonetic characters are in different fonts. Unfortunately, these are not the usual fonts that you are probably familiar with, e.g. Times New Roman, Arial, Courier and the like. These are Doulus, Gentium, Tahoma ...
How to load the Gentium font onto your computer and how to install it, for example, can be found in a document by David Stoppel which, in addition to the instructions on how to install Open Office (the alternative to the fee-based MS Office), contains the relevant instructions.
Please don't misunderstand: you don't have to have Open Office to install the font!