Using Micro sd card with adapter

1. You don't. The SD camera adapter can only be used to copy photos from an SD card onto the iPad. There is no support for writing files onto the SD card from the iPad.
2. If the other device is saving the pictures to the SD card, they must be in a folder called "DCIM" on the root of the SD card. The files must have an 8 character name, and 3 character extension to be seen by the iPad. example: image001.jpg or video001.mp4 for instance.

See here for more: Import photos using Apple camera adapters - Apple Support

Please know that there has been some issues importing videos onto the ipad for the last few updates. It used to work all the time, and I have some older SD cards that I can import videos off of, but not my newer ones. I suspect it’s a SDXC or SDHC issue, but I’m not sure. So if the videos don’t work right there may not be anything you can do since it’s a systemic issue with Apple.

You can also use dropbox or some other service to get hte files off the ipad, that said, you will need a computer on the other end to receive the files and get them onto a card.

There are some special USB/Lightning flash drives that - with a companion app - can be used for file transfers. Kingston WiDrive is one such device, and there are others. They’re not perfect and often take some tweaking since the iPad lacks a file manager. You’d need to do some googling and research to see what ones look like a good fit for your needs and budget