How about applying Limestone ,to neutralize the soil.
Fig trees will not fruit in very acidic soil.
Soil become acidic in time especially if fertilizer were applied in the past.

And check roots for nematodes infestation,they look like black round beans hanging on roots.
If no nematodes found apply thick mulch under tree and a lot of limestone,and next year your trees will make fruits.
They are 2 years old and they made fruits the first year?
Your trees are exhausted,for producing fruits too young.
Well they took a brake this year,but the Limestone and mulch are needed any way.

You should not allowed the trees to produce fruit last year. I have some of my trees 2 years old and produced fruit this year but I thinned the fruit to let them grow and get bigger I never tried the lime stone. I think my soil is alkaline I had to add sulfur to increase its acidity for the blueberry plants. You can test your soil to determine the pH if it is 6 or over do nothing. If you grow blackberry, blur-berry or red-berry you have to get it down to 4

Thanks for the advice. I shall try using some granular lime next year.