I don't know how are you going to implement your service. But by looking at your website it seems that you could do a lot by hand to test if it works, sort of "fake it til you build it"

I built a lot of things that didn't work and with time I learnt to first get customers and then build the product.

I usually buy time saying that we are customizing the product for the client's use case, which it's usually half true. Just be honest about dates.