Error: no node found in netmap with IP

I’m trying to set up an exit node on my Raspberry Pi with Debian Bullseye using the guide on the tailscale website (Exit Nodes (route all traffic) · Tailscale). I got as far as

sudo tailscale up --exit-node=myIP

myIP being the IP of the Raspberry Pi as shown in machines (100.x.y.z).

Even though having painstakingly followed the guide I get the following error:

‘no node found in netmap with IP myip’

How can I proceed to make it work?

Thank you.