Hi Po-Yu,
When using client libraries such as Ruby, initially, you will need to retrieve your
credentials (client ID, client Secret) from the Google API Console, before you can specify them into the client library's properties file.
Since you also mentioned that you already have a refresh token, and assuming that it has already been specified as well in the properties file, the access token should then be automatically created for you each time you run the API via a client library.
Best regards,
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Peter Laurence Napa Oliquino |
Google Ads API Team |
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