Hi, I was having this same issue but with exposing the API to GET requests. It was working when I pasted it in browsers and ran curl commands but did not work in my app. For me, the workaround was to make requests from my server-side rather than my client-side to avoid CORS issues it kept spamming at me. (i.e. in my NodeJS app, I used node-fetch API instead of the client-side javascript fetch API)
UPDATE: Moving to server-side only fixed my CORS issue and still saw the “use_myFunction” errors even though I’m using POST. At first I thought this was a security permissions setting but there was this error saying use_myFunction is not found. According to documentation - use - Velo API Reference - Wix.com - All HTTP requests to the function will be routed to a user created USE() function unless another function is defined specifically for the request’s HTTP method. In other words, if something goes wrong, it falls back to the use_myFunction() version of your method.
As a temporary work around for this, I copied my POST code into my use_myFunction() function to allow the code to still run and return to the user. Basically having two functions with same name but one has “use” prefix and one is “post” prefix.
If Wix support can please make a fix or some insight into this, please let us know.