Question for MAC users

I usualy work with PC and use my MacBookPro only for holidays.
Now i export my Mavic videos from MicroSD to PC by external usb-cardreader. So long, so good.
But if i connect the usb-cardreader to my MacBook it can't read the data.
I know there's a trick that external drives etc. can be read by both, Mac and PC, but don't remember how.
Can anybody tell my how to do this?

For external drives to work on both it needs to be formatted in a FAT32 format. The problem with that is that it only allows for a maximum file size of 4GB. I don't know that this if pertinent to your situation however because it seems that it is the USB card reader that it is not recognizing. When it is plugged into the mac do you see anything when you go into the app "image capture"? Your Mac should be able to read the card without problem. I always use a sd to micro sd card adapter.

The external drive needs to be formatted to exFat that way there is no 4gb file limit and can be read to PC and Mac you do this on a Mac in Disk Utilities.

Problem solved, i formatted the card direct within Mavic and it can be read automatic on both systems. Before i had problems with my old card reader and formated on PC. Had to buy a new actual card reader for the new MicroSD.
For external harddrives exFAT is right. FAT32 can't be read by MAC as i remember.

Fat32 can be read by both but as Jake said there is a 4GB file size limit.

I know this is not the question you asked but I wanted to mention one thing that can be very handy if you have a go pro. If this helps one person then brilliant. You can use the go pro plus account for free for a month. This way you upload direct to the cloud, then you can download direct from the cloud so no need to worry about the Mac reading the sd card.
I am not promoting this just throwing something out there that might help.

https://shop.gopro.com/EMEA/subscription/gopro-plus-monthly/GoProPlusMonthly.html

https://gopro.com/help/articles/How_To/Auto-Uploading-Your-Footage-to-the-Cloud-With-GoPro-Plus