Depending on how the okra is prepared it's sometimes normal for cooked okra to become slimy.
If the okra is slimy though and has a bad smell to it or become mushy when raw and have turned brown then the okra is bad and should be thrown out.
But if the raw okra is just a bit slimy in texture and is still green and not smelly then the okra is okay and safe to eat.
If you want to get rid of the slimy texture of the okra before cooking the okra you can soak the okra in some vinegar for around 30 minutes before you cook it.
The vinegar can help reduce the slimy feeling of the okra when cooked.