V3 API integration

Hello Again,

We have started to integrate V3  API.  We have completed following step.

1. Generate CODE - To recreate case, I am providing detail here. Using the following URL, You can generate the code.
https://authz.constantcontact.com/oauth2/default/v1/authorize?client_id=ec179f3f-5e8e-454c-a015-ec35ab0bce53&scope=+offline_access&response_type=code&state=qwerty&redirect_uri=https://caasafety.com.au/

2. Generating token - Using CODE we are getting using above URL we are trying to generate access token. Following detail, we have used for that. : https://prnt.sc/fHNkDgHFIbU0
You can check the error we are getting. So we need help to move forward from here.

https://authz.constantcontact.com/oauth2/default/v1/token

Parameter : 
code: [Take latest from Generate CODE URL]
redirect_uri:https://caasafety.com.au/
grant_type:authorization_code
client_id:ec179f3f-5e8e-454c-a015-ec35ab0bce53

Could you please guide us what is wrong here?