Q.Green beans
My beans are blooming. Should I fertilize again when small beans appear?

Fertilizer is generally worked into the soil at planting and a 2nd application just prior to blooming.
I do feed my bean with Epsom Salt during their growing period. I feel the results are better with this treatment.
https://www.gardeningknowhow.com/edible/vegetables/beans/tips-for-growing-beans.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/epsom-salt-gardening.htm