I logged in to Moaform, but the forms that I made were disappeared.

Moaform does not arbitrarily delete forms in any case. If you do not see the form you created when you log in, you may have logged in with a different account.

Users often have multiple Moaform accounts. Sometimes users create forms on an account and log in to another account later so they cannot find thier forms.

If you don't see the form when you log in, please consider carefully whether you are using a different account.