how much are my reward points worth

We are end users like you here to volunteer technical support, not financial advice. You need to contact Apple or the issuing bank for info on credit card perks.

Reward points?

If you are referring to points here on the forum, see: Build your reputation and get rewarded in the community - Apple Support

You will need to contact Barclay for that information. Log into your Barclay Account (I am in the USA and that link here is barclaycardus.com) and look there. You can always call them if you need more details.

I have used them several times to get 18 month interest free financing. However I understand that with the advent of the Apple Card Apple and Barclay have severed their relationship. I googled and found a Bloomberg.com article about it.

https://www.bloomberg.com/news/articles/2020-09-15/apple-ends-barclays-credit-card-partnership-ahead-of-new-devices#:~:text=as%20its%20bank%20partner%20to,well%20as%20gift%2Dcard%20bonuses.