Having just started using Alexa, and wanting to voice control some Blynk projects, my natural first move was to Ifttt.
Sending Restful commands it certainly worked .... But .... I don't like open ports or having to use the 'Trigger' word.
Something that has obviously been around some time but not known to me until now is Habridge (GitHub).
This can sit on a Pi Local server quite happily and works with Alexa. It will allow devices to be searched for, and amongst its capabilities, can easily send Restful commands. No more 'Trigger', no open ports, and multiple commands sent.
For someone who lacks Linux knowledge, sure, it took a little while to get going ( had to use script instead of ctl method )
but it was definitely worth the effort.
For me, Blynk fills all the boxes, and now to voice control it via Alexa it's even better!