This class represents the OAuth2 access token used for authentication with the MTN MOMO API.
The access token string used to authenticate API requests.
The number of seconds until the access token expires (e.g. 3600 = 1 hour).
The token used to obtain a new access token when the current one expires.
The number of seconds until the refresh token expires.
The scope of access granted by the token.
The type of the token (e.g., Bearer).