Two Factor Authentication (2FA)
If you currently receive this code by phone, then it is important to set up an alternative method* to receive it, in case your phone is not available, working, or receiving a signal. You can sometimes tick a box to say 'Trust this browser', but if you are in the habit of 'cleaning' your device, then that may not work.
*Look at the settings of your account.
You can read all about the subject here: https://bit.ly/3PBm4Pp