I just purchased a 2019 4Runner from Avis Rental via a dealer. I guess Avis didn't pay for the navigation feature, although the APPS has the navigation option and there is the SD card slot in the head unit. Or a customer removed the SD card. When I press the Navigation icon, the unit says the SD Card is missing. (The mats, the 2nd key and the manual were missing too. All items I made them provide by pulling from other 4Runners on the lot.)
Anyway, my research shows the SD card is #862710E072. Toyota wants $169 for it, but eBay has OEM cards for around $50-$70. Make certain you buy from a reputable US based seller with the return option.
I'm going to purchase one from eBay and install it. I'll let you know how it goes.
I updated my 2014 Kia Sorento in a similar fashion and it worked great. (By the way, the Kia SD card update was only $29 direct from Kia's US website.) Love the FB's Day Off reference!