Use a well balanced (10-10-10 or20-20-20) all purpose plant food (such as Miracle Grow or Shultz) and apply it as directed on the package for indoor container plants.

Thank you.

Pay close attention to the numbers.

Most indoor 'plant food' is very high in nitrogen. For example, Miracle Gro water soluble plant food is 24-8-16.

Nitrogen will grow a whole lot of very bland leaves.

It's better to use a balanced fertilizer (all numbers the same), or something close to a balanced fertilizer. I recently bought some 'organic tomato, herb and vegetable' plant food that was 5-4-6, with added calcium and micro-nutrients.

In the Miracle-Gro famliy, the "Shake 'n Feed Tomato, fruits and vegetables" stuff is a reasonable choice (9-4-12 plus micro-nutrients), although I don't really trust 'slow release' products that claim to last 3 months if you're putting it in small containers.