Hello there and thank you for using Ask Extension. 

You squash plant does not appear to have any disease or pest issue.  Blossom end rot is caused by a calcium deficiency, but is usually due to overwatering which makes it more difficult for the plant to uptake calcium. In addition, BER affects the blossom at the end of the squash.  But your flowers are wilting before the squash develops.  Here's some information about blossom end rot, but I don't believe that is the problem.  https://pender.ces.ncsu.edu/2020/03/why-are-my-squash-rotting/

It appears to be a pollination problem.  As you no doubt know, zucchini have male and female flowers on the same plant.  The flowers will drop if they are not adequately pollinated.  Here's what it looks like.   https://aggie-horticulture.tamu.edu/vegetable/problem-solvers/cucurbit-problem-solver/cucurbit-fruit-disorders/poor-pollination/

So, it could be that the male flowers are wilting. Or, maybe the bees have not been visiting lately.  You could pollinate the female flowers mechanically yourself.  Here's some information on doing this.  https://extension.unh.edu/blog/zucchini-plants-flowering-not-producing-fruit

The plant seems to be healthy otherwise, and the season is still early.  Good luck.

Jeff C

Plant Clinic