Unable to add new devise to Alexa app.

[Bens]

I purchased a no name wi-fi water leak level alarm and connected it to my home network using the TOYA app.  It also connected to my Alexa app and I was able to set up a routine.  It worked so well I bought a second one.  It connected to the TOYA app and works with it but I cannot get it to connect to the Alexa app.  I’ve been trying for days and can’t seem to get it to work.  I even bought a third one to rule out the second one might be defective.  Can it be I can only have one of the same sensors connect to Alexa at the same time?  Any assistance would be greatly appreciated…  Thanks