The name of the connection is of course custom, but one of the Auth0 documentation files had an example with something that worked. It says it sends a reset-password e-mail, but it doesn’t actually do anything.
https://auth0.openai.com/dbconnections/change_password?email=<your_email_here>&connection=Username-Password-Authentication
Probably even better to do a POST request, like described in the Auth0 documentation. But still it does absolutely nothing.
curl -iX POST 'https://auth0.openai.com/dbconnections/change_password' -H 'Content-Type: application/json' -d'{
"email":"<your_email_here>",
"connection":"Username-Password-Authentication"
}'