Hi, I would to maximize the usage of a 2.5 Gbps subscription plan to ISP.
However, the ONR provided has only 1 Gbps interfaces and does not support link aggregation.
Is configuration in the attached possible? Or what would be the correct/better setup?

The correct setup is to ask your ISP for an appropriate ONT/ONR which would have a 10GBase-T interface or something.
Give 'm call.

If you pay for 2.5 Gbps you should get hardware which supports this bandwith.
Even with two interface each with one gigabit a single stream would be limited to 1 gigabit.

Have spoken to them and no solution was offered.
I’m stuck with this ONR.