Dual default route

Hello,

my setup has 2 routers (LTE routers) which are connected to the local network. Orbi is the default gateway for the clients on the network and Orbi has single default route which points to either of the LTE routers - usually the one which has better connection. The functionality I am after is something which would enable Orbi to detect whether internet is/is_not available and if there is a problem with the internet, Orbi will automagically switch its default gateway to other router.

thanks !