How to Install Purchased ReadSpeaker Voice into Captivate 2019

Hello - Would anyone be able to provide me with (or point me in the direction to) documentation on how to get a voice we purchased from Neospeech/ReadSpeaker into Captivate 2019 (v11.5.5.553)?

My actual issue is that I am on a Windows 10 laptop and I have installed the ReadSpeaker voice into the Adobe Captivate Voices 2019 x64 folder based on the instructions provided by the ReadSpeaker company. I can see the voice (Ashley) in the list of voices in Captivate, but when I select that voice it instead plays as Microsoft David.