@Lokatsu938
Please use the same ID and password to login to the cloud website first.
https://www.tplinkcloud.com/
If it works, try to change another device or web browser to login again.
Besides, you can use the default one which is admin to give it a go.
Still the same, you can hard reset it and relogin with admin. And you need configure it to make it work again.
May it help.