This is currently not possible. However, our engineering team is working on a solution to cross-region load balance App Engine Flexible and Standard. There is no ETA for the release but you can follow the Public Feature Request <https://issuetracker.google.com/65039982>for updates.
It seems this is a familiar question on the community. I recommend posting questions to these currently ongoing discussions for better tracking purposes. You can visit them here <https://groups.google.com/forum/#!searchin/google-appengine/multiple$20regions|sort:relevance/google-appengine/Upxbns9ZpAc/PdTaQqBeBwAJ> and here <https://groups.google.com/forum/#!searchin/google-appengine/multiple$20regions|sort:relevance/google-appengine/svMhwuFC5zk/ORjQNWdDBgAJ> . -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-appengine+unsubscr...@googlegroups.com. To post to this group, send email to google-appengine@googlegroups.com. Visit this group at https://groups.google.com/group/google-appengine. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/42694f12-a311-4749-8b28-731ea725ab28%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.