OpenVPN is not working while business vpn is on

Hello, 

i have two location where i have two orbi pro.

they are connected throught orbi businbess vpn as site to site.

it's working very good, still the distant site is only accessing to local network on the central site.

what i would like is the distant site access internet throught the central site, wich is not happenning.

so i tried to activate on the central site the open vpn feature, still while trying to activate it and click on apply button, nothing is happenning

i have the SXR30 as central site router 

and the sx80 as distant site

please can you help on this?

thX!