It depends. If there's a share id (?igsh=xxc) in the link usually no, but if you remove it usually yes. Opening more than a few posts/stories will result in a popup to sign in, but at least the core page and introduction should be visible.

Change the URL from instagram.com to imginn.com. There are browser extensions which will do it automatically.

Doesn't work..

Try switching to desktop mode

it still forces you to log in when you scroll and you can't view any post iirc. Maybe solvable with ublock filters or some console commands but I haven't bothered

You can view posts by opening them in a new tab.