Z2JH Google OAuth Extra Param: prompt=select_account

Hello Jovyan(s)!

I am attempting to deploy JH Kubernetes and things are going well. However, I find that if I am logged into my personal Google account, and connect to JH, it sends me to Google Auth and I am forbidden (403) because only my educational domain is allowed. I can force good to prompt me to select a account by adding &prompt=select_account to the end of the URL. In the JH OAuth code it appears there is a extra_param that can be set to include this, however, I am unable to figure out how to add it to my yaml config file. Could someone recommend a config reference file or the proper formatting for this in the config file?

Thank you.