I can't login (Incorrect username or password)

I created a new account. Then I tried to log in but it says (Incorrect username or password)
How can I fix this problem? At first, I thought that I wrote the wrong password. Then I changed my password several times but it still says the same message (Incorrect username or password).
Then I created 4 or 5 accounts but it still gives the same message

Please someone helps me. I’ve been trying to play this game for a week.