how to access with api url including credentials. nextcloud desktop client

[David Kebler]

I have the webdav server spun up. I'm having no issues accessing it via nemo and cadaver but both those prompt for credentials either before/after initial connection.

Now I want to try the nextcloud desktop client which will work with any webdav server (e.g filerun)
https://github.com/nextcloud/desktop

The issue is the client url I'm putting in fails because of authentication (apparently I need credentials in the url or to use a different endpoint that will take me to the client credentials dialog?)

server says
2022-01-05T10:55:17.519-0800 info login attempt {"username": "", "remote_address": "127.0.0.1:41252"}

client says

I assume there is some rest api? Any documentation for that or is that the point of a webdav server it must use standardized api (where documented?)

So what would be the url to pass credentials? Anyway some help using the nextcloud client and your server. Maybe you have some experience. Thx.