How to get the access_token of a user using postman

[Manas]

I’m a very new okta service.
I played around postman collections to get the access_token.
I believe the following endpoint is to get the access_token,

endpoint: {{url}}/oauth2/default/v1/token
request: POST
Body:
{
grant_type: authorization_code,
redirect_uri: http%3A%2F%2Flocalhost%3A9999,
code: {{code}}
}
Authentication:
{
Username: {{clientId}},
Password: {{clientSecret}}
}

I’ve no idea what to pass it to code parameter.

Later I found an endpoint to get the code,
endpoint: {{url}}/oauth2/v1/authorize?client_id={{clientId}}&response_type=code&response_mode=query&scope={{scopes}}&redirect_uri={{redirectUri}}&state={{state}}&nonce={{nonce}}

Again I’m confused in the state and nonce parameters.

Can someone help me here?
Thanks in advance.

[phi1ipp]

You need to get an idea of how OIDC flows work. To be able to get an access token you need first an application created, which will send a user (or user credentials) to Okta for authentication first. And then depending on a flow selected, it can either return a token back, or authorization code.

state is random value your application sends to authz server and expect it to return back the same value, so it to protect/save the state of the application. Nonce is just a random value sent by the application. authz server checks it to prevent replay attacks.