Buying Fractional Shares in £VUAG

It’s payday today and I wanted to buy £100 worth of shares in Vanguard S&P 500 which I hoped to do on a monthly basis, I put in £100 to buy but I only ended up buying one whole share at just under £60.

I understand there are fractional shares on Freetrade since I have bought others on here but I see no option to commit a further £40 and buy on this occasion. I type in the £40 but the “Review Order” button is greyed out.

Am I being blind and missing something really obvious or are fractional shares not a thing for index funds?
Thank you for your help.

5 posts were merged into an existing topic: [Feature Request :wrench:] Fractional UK shares