Issues connecting to custom DB

My team recently set up a custom db to use as an alternative to Supabase/Firebase. We're planning to use API calls to access and store data. We have set up the first API call to initiate user sign-up. Upon testing the API, it said it was a success. However, once we set up the actions on the actual app screen, to send data collected from the sign-up page, nothing happens. We see that the form is validating but it stops at the API action since the last action is to navigate to the next screen. Based on the images I've attached, do I have everything set up correctly, or am I missing something?

https://preview.redd.it/0yj4fherpeqc1.png?width=2482&format=png&auto=webp&s=fe53738a0eefb3a84e2b1b33496dde7eee74cb4e

https://preview.redd.it/2llwnherpeqc1.png?width=2240&format=png&auto=webp&s=15ad293d031e3f94dbc63ba2743b064dc8b00867

https://preview.redd.it/x0f59ierpeqc1.png?width=2184&format=png&auto=webp&s=62bb6fbf701a86c1122bd7e73a8342751a8b1761

https://preview.redd.it/k6kbrherpeqc1.png?width=2214&format=png&auto=webp&s=f48bcc77c7029d714a11e5f998c95708cfbe0829