Return the plug to a Generator Hookup vs car charger

[Lefebvres090428]

My house had previously been wired for a generator (probably not by code to this day) but previous homeowner disconnected and instead hooked up car charger to that circuit. I would like to place it back to a generator hook up plug for emergency power. I have included labeled pictures of outside main panel, inside main panel and the sub panel next to the inside main panel.

I am guessing that now a days code would call for an interlock switch outside on main panel. I usually just before always switched the main off before powering up the generator on houses that I owned with a generator plug and no interlock. Obviously I didn’t want to back feed the grid.

Is there a way to re hookup the generator plug looking at the pictures since the charger is now gone? How would it be done with an interlock? Also how would it be done by busing the old plug and the existing circuit?

 

[Lefebvres090428]

I forgot to mention that I have the correct receptacle for the cord that I will wire in. (The male vs this female pictured) my cord plugs male into the generator and female to the home. Plus I don’t need a live cord with a male end laying around.