No problem, on the login screen, you have the option to indicate that you have forgotten your password. An email will be sent to the linked email address of your account (if an account is found under this email address).
In this email, you will find a link that you can use to set a new password. Once you have done this, you can log in again with your new password.
To log in, you must have created an account on the application and confirmed the account by clicking on the link in the sent email (this email may be in the spam folder).
If you cannot log in to the mobile application, it may be that your device is not connected to the internet.
If this is the case, maintenance may be in progress on the servers, making them temporarily unavailable.
On the Airsmart application you always have the option to log in using your email address, so if you have forgotten your username you can simply replace it by using your email address when logging in.