Yandex is a Russian cloud storage that give you 10 GB of free storage. You can add it easily in Air Explorer.
Once you have registered in Yandex, you just have to add your username and password in Air Explorer to add the account.
If you have a Yandex account and you have enabled 2factor authentication then you have to do one step more to add your account in Air Explorer. You have to enter in your Yandex account panel and generate an application password.
Then, add your username and the new password that you generated in the application password.
Now, you can use your Yandex account in Air Explorer.