UPDATE: we switched the ignition relay with the headlamp low relay from the engine fuse box, and nothing changed. We also checked the “ENG CONT INJ” 10A fuse and other fuses under the dash and they were good.
You can hear the fuel pump priming every time the ignition is on, and the fuel rails are definitely getting fuel. Like I responded earlier this evening, we’re going to pull injectors next time.
So, so far we have checked the intake/plenum, the spark plugs, coils, fuel rails/lines, the fuel pump (and replaced the old one to no avail), ignition relay, fuel pump relay, immobilizer (like someone here suggested, and watched the YT video linked with no success), and the “ENG CONT INJ” fuse.
If it was your car, what would your next steps be?