custom tts voices

there was a post made 3 yrs ago about this and still no updates. if you have a custom text to speech installed, how do you use it in overwatch, or what is the right kind of tts format to be searching for to download that it would allow you to select it alongside the default microsoft voices. i can see theres some other microsoft voices for download that most likely it would accept, but i dont know about custom ones. this is nerdy because you need knowledge of how to download non standard voices in the first place