I am currently developing Oauth for garmin connect api in ruby. I have successfully managed to get access tokens via 3-legged omni authentication but, the problem is access token expires after some time and users are required to log in to their accounts everytime it expires. Is there any refresh token provided by garmin as i have searched a lot about it on internet and didn't found any thread mentioning it & no reference in garmin_connect_oauth_specification document too. If so? What are the steps to retrieve refresh token, what is the request url, what parameters do I need to send with request?