Emit a one-time-login JWT token for a specified user

This endpoint produces a "one-time-login" JWT token for one of your users (patient or provider) that can be redeemed to login the user against the Nabla API. The one-time-login token is short-lived and, as its name suggests, can only be redeemed once.
The typical flow is the following: a user authenticated against your backend needs to access the Nabla API, the user's frontend client (securely) requests a one-time-login token from your backend, your backend uses this endpoint to generate the one-time-login token and (securely) returns it to the user's frontend client, the user's frontend client redeems the token against the Nabla API to login, the user's frontend client uses the access & refresh JWT tokens for the session started with this login to access the Nabla API.