Able to get access token only for the first time and subsequent requests are failing - google-oauth

Question

I use the below url in the browser to get the refresh token and it works fine(I get the prompt to authorize access and all that):
https://nestservices.google.com/partnerconnections/{project-id}/auth?
redirect_uri=https://www.google.com&access_type=offline&prompt=consent&
client_id={oauth2-client-id}&response_type=code&scope=https://www.googleapis.com/auth/sdm.service
Then I take the refresh token from above response and run the below command in terminal and it gives me access token:
curl -L -X POST 'https://www.googleapis.com/oauth2/v4/token\?client_id\={oauth2-client-
id}\&client_secret\={oauth2-client-secret}\&code\={refresh-token-from-previous-
step}\&grant_type\=authorization_code\&redirect_uri\=https://www.google.com'
If I run the same above command for one more time, it fails with the error. I tried waiting for couple of hours to even a day but still same result :
{
"error": "unsupported_grant_type",
"error_description": "Invalid grant_type: "
}
Why is it working only for the first time and subsequent requests are failing? I am using this documentation(https://developers.google.com/nest/device-access/authorize) and don't see anything related to this.