dometic hardwire kit 12v to bed

I'm looking to run a 12v outlet to the bed with the dometic hardwire kit to supplement my ecoflow battery during driving. This kit is 10g wire and a 15amp fuse, what's the best way to hook this to power and avoid killing the starting battery?

Tap into an ignition switched circuit or add a switch inline with the harness?

https://www.dometic.com/en-us/outdoor/coolers/accessories/dometic-hardwiring-kit-dc-222471


My current set up is an ecoflow river max connected to 100w solar panel on my shell powering a dometic fridge. It works so-so as it is but the solar doesn't usually keep up to keep the battery topped off after a few days. Now im looking to run 12v to the bed so the battery can be charged while driving instead of relying on solar 100%

 

I'm doing the same and will just run a relay to power the dometic kit on ignition to preserve the battery when ignition off. Portable folding 220w panel for charging when stationary.

 

which circuit are you using?

this kit is just wire and a 15a fuse, do I need to add a relay?