I’ll give you 3 different ways to do this:
1. Use this theme component
Make a custom sidebar menu with the link to /login and use this setting in the theme component:
2. Use CSS in a new/exsiting theme or component
If you just want to add a link in the top section under My Posts, you can add the link to /login via the More - Customized this section link like this. For example if the link is called “Login or Signup”:
Then go to a theme or theme component and edit the html / css like so:
Keep in mind that the link references in that top section are case sensitive:
.sidebar-section-link-wrapper[data-list-item-name="Login or Signup"] {
display: none;
}
.anon .sidebar-section-link-wrapper[data-list-item-name="Login or Signup"] {
display: block;
}
result in incognito / anon view:
3. Use the following theme component
Yes I made a specific theme component ages ago that does this. It also does the reverse - displays a section for members only (logged in users).