How hide Login button in header

Also, to show the login sidebar link to only anonymous users, then you can use this code instead:

.sidebar-section-link-wrapper[data-list-item-name="login"] {
    display: none;
}
.anon .sidebar-section-link-wrapper[data-list-item-name="login"] {
    display: flex;
}

.d-header .login-button {
    display: none;
}

I think the data-list-item-name is case sensitive, so if your link is “Login” then it should be the same in the CSS code.