When first planting, throw a hand full of crushed egg shells (I save them up all winter) in the planting hole, and about 3/4 cup of bone meal.
After your plant starts flowering, top-dress around the root line with more bone meal and water it in.
I do this for tomatoes, peppers, eggplant and summer squashes. Works like a charm!
This late in the season, you may want to apply a dose of liquid bone meal so the calcium gets to the roots quicker and new fruits should be free of blossom end rot.
I use Jobe’s brand for the powdered bone meal and Down to Earth brand for the liquid bone meal.
(Again, NOT a paid endorsement, LOL!)
Thanks so much!