TL;DR: I pitch them an inexistent feature on Twitter and they bought it and so I spent the night building it.
I've always read that usually the first customers are the hardest. For me a bunch of cold tweets and DMs did the job.
First I looked up the existing no-code companies on Twitter.
Second I'd send a cold DM (text below) or an enquiry tweet "hey [tool] are you interested in being featured on nocodery.com ?"
Most of the tweet would have an answer along the line "sure send us a DM with the information"
And then I'd and this DM:
"Hey, I'm one of the founders of nocodery.com a nocode job board.
I'm reaching out to some nocode tools to inform that we will have an area dedicated to those tools for free
nocodery.com/tools.html
We also have a premium version that includes a verified badge, unlimited free job offers and embed tutorials on the page for $119/ year (less than $10 per month).
As a launch promotion, we are offering a month of promotion on our main tools page and newsletter valued in $100 for free to the first 3 verified accounts (there's only 2 left)."
This DM had a couple of points that I think are important:
The tweet and DM either got the conversation started on Twitter or a mail thread asking for more info.
Funny fact is that we did not have any of this implemented until the first customer came along (Bildr) and when that happened I spent one night coding everything so it was ready when the money got through (this was during the time my forms were not working)
This way I was able to test a feature and market fit without spending any money or time coding that feature beforehand.
This week we got Adalo (top no-code app builder tool) to buy the premium and this time they asked if we had a page with all the info where they could purchase and, yes we didn't but it happened in one night again (nocodery.com/premium)
I still use the same pitch with other no-code tools. I had contacts from tools that asked me to save a spot (Wich I hope to post about it soon).
And the good thing was that even if I didn't got a customer I got a contact that I could talk and understand their pains so I can pitch other features (that I have not developed yet)
So, don't be afraid to sell what you don't have as long as you know that you can build it fast enough. In the worst case scenario you will end up with a bunch of contacts that you can talk and maybe help them out in any other way.