New to the forum, looking forward to the group expertise and support

2018 Lexus ES350 and we just took a trip using navigation. Some places I followed signs and the navigation map showed us traveling through swamps and land with no roads and of course was confused until we came to a place where the map had information. My map version is dated June 2017 in 2018 vehicle.

I have updated the map SD card on some of my other vehicles, just downloaded file and burned it to a SD card and plugged in and went through he process of vehicle finding new update, turning vehicle on and waiting for update to load, turning off and the on and installing updates and following prompts--does take some time but not too difficult--saw a Youtube video for ES350 and it is the same.

Where can I either download the file to burn on a micro SD or where can I purchase an updated Micro SD card for our 2018 Lexus ES350

Thanks for the help