Was about to post the same question yesterday , but came to the conclusion that we’d have heard about it already and as @SweetBlitzhas stated the uncertainty around being able to complete the planned revised races would make it impossible to price.
Currently eyeing up the 3 months @ £25 offer which will cost little more than the £9 per race the cancelled season pass advertised if we get all 8 scheduled races.
Holding off on taking that offer up until the last day (July 2nd) to maximise coverage and get a good chunk of the Indycar season as well.
Are you based in the UK whilst attempting to take up the offer and not in another country (including on holidays) ?
If you are in the UK, then perhaps try switching the power off to your Router for about 30 minutes just in case there is a rouge IP address and the NowTV system thinks you are outside the UK.
Should you be using a VPN in the UK, then temporary disable it when attempting to purchase the 3 months at £25 per month sports offer.