@user_711725607157890_711725607157890
That sounds like a good solution. I'll give it a try.

@joseph_1979
Thanks for the reply however this didn't work for me. If i've got this right, two files are generated when recording a voice clip in the app. One is a .pcm and the other .wav. All files created are saved into the audioFileCache folder. The PCM and wav files that are uploaded to the camera (save button) are located in the temp folder and named doorbell_sound.pcm and doorbell_sound.pcm.wav.
I tried replacing the doorbell_sound.pcm.wav with my own .wav file, then hitting save in the app, but that only resulted in the clip recorded via the app to upload.
I'm happy to keep to forge on ahead only if it helps someone else, but what I've settled on for now is to record a message in my own voice. Next option might be to engage a voice over artist
PS: Phone is a Samsung S20FE 5G

@neptune_654294262100039
Update: I found the folder location in my android \\Internal storage\Android\data\com.mcu.reolink\files\reolink\audioFileCache.
Note: The Android folder can only be viewed using a PC connected by a USB cable.
Each audio clip in the folder has a .wav file and a matching titled binary file. I tried dropping my .wav file into the folder but as expected the app wouldn't recognise the file as there is no way to generate the binary file that would usually go along with it if the clip was created through the app.
I guess that's the end of the line and I need to record the clip using the app and phone microphone.

Looking to find a method of uploading a mp3 or wav file to be used for a quick reply message. The app has the ability to record a message in my own voice which saves directly into the app (somewhere), but I'm wanting to use a text to speech file that can be uploaded. I could play the TTS file from my PC and use my phone to record it into the app, but looking for something more elegant that gives clean clear audio. A check through my android phone internal storage didn't reveal a folder where the voice messages would be stored.
Video doorbell POE. v3.0.0.2017 connected through local LAN to the NVR.