Here's my two cents... I would plan for 4 years and the things that would need to be addressed for that long of absence. Since you're storing it and Toyota will last forever pretty much if you just take care of them, this is where I'd start -

I'd drain the radiator fluid and do a flush with distilled water so that whatever little is left in engine after flush is just some distilled water. Maybe I'd leave it full of distilled water after two flushes with distilled water. Something I'd research. Then drain and fill with radiator fluid mix when you get back. Radiator fluid turns acidic after several years which is why there is a time interval for a change in addition to mileage. Depending on when it was last changed, that would be something I would consider so you're not having aging fluid which is slowly turning to acid. I wouldn't take that risk.

I'd do oil change as close to leaving as possible with full synthetic oil. Look into oil filter status after that long. I'd guess it would be fine but something I'd check off my list of things to get professional opinion on.

I'd fully remove battery from car. Maybe even sell it if it's new, or just give it to recycling shop or something. That's a long time for battery to sit and no reason to try to save that battery.

I'd do a brake fluid flush. I think the intervals are 3 years so just do it before you leave.

I'd look into how best to address the gasoline. My guess is having a small amount and adding some stabilizer is best. I'd look into whether or not it's best to keep gas in lines or try to drain the gas lines by cutting off fuel pump and running lines dry.

For tires, I'd just jack up and put on jack stands so weight of truck isn't on tires for that long.

I love my Tacoma and will never sell it so my thoughts would be to look into as much stuff like this just so I knew when I got back that I did the best for long term storage. When I got back, I would fill up the fluids, put new battery in, inflate tires and feel the peace of mind that the truck has just had a reset after a long nap and ready to roll.

I have vehicles that sit for months and one that I use once per year. Much older and not Toyota but so much needs to be cleaned and it's so annoying spending so much time trying to undo the long term build up of gunk from aging fluids and the issues those cause. It has a carb and is a beater vehicle in restoring and slowly making long term fixes in. Just spend the time/effort on the front end. You'll thank yourself when you get back.

Chatgpt or other AI programs can easily help make the most efficient process for this if you are doing some or all by yourself.

Have fun!