Look at the FT universe spreadsheet…
Ping the finkiAPI use the ukDividendYield and ukDividendYieldv2 functions
For example, BNKR
https://finki.io/callAPI.php?isin=GB0000767003&function=ukDividendYield
or
https://finki.io/callAPI.php?isin=GB0000767003&function=ukDividendYieldv2
(since calc methods of div yield can vary)