To apply for standard access please follow the instructions listed in this
guide.
If you are getting rate limit errors with Developer scope, you can apply for standard access. Once you have your access approved, you can make unlimited API operations and unlimited report downloads per day. If you are getting rate limit errors with Account scope, upgrading the access to standard access will not help. You will need to
slow down and retry the request after the time specified in
retryAfterSeconds. You could also, look into the
best practices to avoid the rate limit errors. Let me know if you have any questions.
Thank You,
Milind,
AdWords API Team.