General Info: Astrea 42 convection microwave/oven

[SSD]

We purchased a 2019 Astrea which came with no oven/microwave. We are going to install a convection microwave/oven unit which only draws 15amp, looking for advice. It appears the 20amp circuit labeled for the microwave in the 120vlt panel has already been used for something else. We tried to chase out the cable connected to the microwave circuit, but was unable to locate where it goes. After looking closer at the wire diagram we notice that there is another oven connection under the nav station on a fuse block, within this wiring diagram it shows a 30 amp circuit for an oven. We were able to find the connection point and the 30amp fuse has been pulled and is just sitting above the plug in spot, the wiring diagram on this inverter system under the nav station is not very clear. Looking for any advice possible on weather to connect the conv micro/oven to the inverter under the nav, or to continue chasing the micro circuit in the 120vlt panel.