I want Alexa to retrieve phone numbers using slot values, that would then be passed through my API. However, the custom slot type: AMAZON.NUMBER seems to be malfunctioning and doesn't take in the numbers correctly. Looking at other similar questions, the solution provided seems to be AMAZON.LITERAL but reading other forums, it suggests not to use it anymore as custom slot values are more efficient. I tried making using both single number slots and defining 10 custom number slots but neither seems to be working.
Additionally, my service runs entirely on APIs so your account linking service would not help me either. Are there any other solutions you can suggest?