1) The client application submits a POST request to the server with data:
1.1) Options:
grant_type = password — authorization type
scope — required role for user
username — user login
password — user password
1.2) Headers:
Content-Type = application/x-www-form-urlencoded — request body type
Plus, client authorization is required, for example, you can select the BASIC type:
Authorization = Basic aWQtalU4NXNoTnNqVUlpWGQ2MDJhTXhtVjFqSmlPTUdSSko3ZHJHeTRCSGlFZEN0SVk6UWNxUVl0OExRWVVEbDdtMk1KOVNFNkFxYklKOE9MWHdnNkJTSVRnTEFjMHpKcXBRY3I= — соединяем через двоеточие client_id:client_secret — and encode the resulting string into BASE64 format
Example request in cUrl: