Postcode invalid, can't register

Problems Fixed
#1

I am a newbie here and just tried adding my new PV array with my postcode in the UK and I get “The UK postal district ‘BB18 6LF’ is invalid, expecting ‘AANN’, ‘ANN’ or ‘AN’ format e.g. LU7, EH33 or SL1”

I tried without the space but the same message. The postcode hasn’t changed for over 23 years !!
Please would you fix it for me?

#2

It needs just the postal district “BB18” rather than the full postcode