Call Backend API without SPA


I’m new to Auth0.
I have a Spring boot API (based on the quickstart) and a SPA application to access the API - (based here)

Now I’m wondering since I have the SPA application (credentials - client_id, secret, etc.), can I simulate this using just cURL or postman? I don’t want to use the SPA since I wanted to only test the API as a user.

So technically, what I wanted to do is to simply call my API like

 curl -H "Accept: application/json" \
      -H "Authorization: Bearer ${jwtToken}" 
      -X GET “${apiEndpoint}”

I’m trying to figure out how to get the access token but to no avail.

Thank you!