How long can I look at a tour Panoramr or my photographer offered me?

The link in the email works for 14 days, without an account, while the offer is open. Nobody else can see the tour in that time: anywhere else it is linked or embedded it says Tour unavailable until it is yours.

If you do not want it, you need to do nothing: the offer runs out on the date in the email. For a tour that Panoramr offers you after its maker closed their account, the tour is then kept until the end of its 12 months and deleted. To take it over, click Take over the tour in the email and choose a Vault: see A tour of your place was offered to you. When your own photographer or agency offers you a tour, its link also works for 14 days and the offer stays open for 30 days: see Hand a tour over to a client.