You know how to access the SD card, right? Simply just delete the files to erase the memory.

You should learn SD card to know SD card.

Anton L.Z. wrote

You know how to access the SD card, right? Simply just delete the files to erase the memory.
https://www.mobiledic.com/android-topic/delete-everything-on-android-phone.html

Obviously, it is one of the essfective way , but the deleted data can be easy recovered back on memory ,we need to permanently delete them on phone memory ,

Usually old files will be replaced by new one when the card is full. If it didn't happen, then it could be some files in the sd card is affecting it. Try format the card.

Can we use memory sd for https://mobile-phone-tracker.org mobile recorder on Android?

The data simply deleted from your SD card can be recovered, if you need to erase your SD card permanently without recovery, you'd better use an Android eraser tool.
Here are two tutorials:
https://www.samsung-messages-backup.com/resources/erase-data-on-samsung-without-restore.html
https://www.android-mobile-manager.com/data-clean/how-to-delete-photos-on-android.html

First of all , back up the important data for your SD card of your phone, then follow this guide to erase SD card on your Android . https://www.safewiper.com/tutorials/android-data-eraser.html

If you cannot successfully delete any file from your SD card or it is kept getting back when you're deleting it, it might be a virus issue. Scan the memory card with a powerful antivirus and also your computer. You should also disable and uninstall any computer data recovery tools or software if any, that might be interrupting in such results.

very useful thanks for sharing good luck