I ám trying tomato tone organic fertilizer recently read about using it on potted figs every two weeks. I am also adding liquid fish emulsion with kelp every other week. Also added lime to the soil to balance ph and provide calcium. Not all my young fig trees have figs yet either..but that may be due to the type of fig they are. Some started getting very productive this year. Some other variables are sunshine heat & water. I have also added manure and compost when l potted them.
Osmocote has also been recommended but l don't think its organic.

guess I'll give ours a little fish and lime at least

How old are your fig trees? what type cultivar are they?
Some of mine were 3-4 yrs old before giving figs, then they give more each year. I have a couple that are only 1.5 yrs old grown from cuttings that I bought this Spring from Bills fig Farm in NJ that have a fig or two on them, called Melazanie. He recommended them for me becaue they put fruit out early and ripen early, which is good for my short summer upstate NY. He grows all his fig trees in pots and recommends Osmocote with his mushroom compost soil.
Potted figs need more nutrients han ones grown in the soil.

hmmm 7 years?
dunno exactly.
we have had figs from them a few times.
But IâÂÂve forgotten everything I leamred and didnâÂÂt root trim, which they badly need.
just gave them some fish and M. Grow which I've done before. Now I'll water them and give them some time.

If you think the tree is root bound in the pot its in you could pull it out and put it in a larger pot for this season...or plant it in ground til the fall and dig it up when it goes dormant...then root trim.