You need a card readers that can be used with standard SD cards. Your laptop or Desktop PC probably already has one. If not, a >$10 portable from Amazon (or >$5 on eBay) will do the trick.
Most portables do both. I bought mine on eBay.
If it isn’t functioning as expected, buy a Transcend reader that plugs into a usb port. The Garmin db transfer is really picky on the card reader for some reason.
I’ve heard so many conflicting things about problems with the Garmin Aviation Database Manager. I do some if my club’s G1000 data updates and have not seen problems since the GNS series which used a special reader/writer.
I seem to recall that Garmin had an aversion towards 3rd party SD cards with the original GTN650/750 and they really wanted to you buy theirs. The later 650Xi/750Xi along with the 2-inch navigators are much more accommodating.
Any 32GB or less SD card with a FAT32 format should be fine in spite of Garmin’s previous communications suggesting otherwise. I’ll throw this stink bomb out there, though….Flightstream 510 for the win.
Pricey for what it is but I love the wireless updates along with the other capabilities.
Most current Garmin card guide authorizes the use of open market SD cards, with a warning about off-brands. They’ve actually been using SanDisk for years. But they still technically require the branded TSO cards for some units.
This is because the terrain database lives on the card with the non-Xi GTNs. So the TSO requires that the card be TSOd also.