Beginner Gardening: What did I do (or not do) to my basil?, 1 by Diana_K

Diana_K wrote:
Basil are short lived.
Once they have set seed, the parent plant considers the job done, and dies.

To keep them living and producing more leaves you need to keep pinching off the flowers that try to form before they get too big, and pinch a few of the tallest stems to encourage them to branch.

Even now, you could try removing all the flowering stems down into the leaves, see if it will sprout new growth lower down. It sure could.

Other than that, bright light (full sun in the milder seasons) or a grow light, if this is a north (dim) window.

Here is a copy of your picture.
The circle shows some leaves with flowering stems. Trim lower down than these.
The arrows show some good places to trim.

I would also try a small amount of fertilizer that is high in nitrogen, see if that will encourage more leaf growth.