How much filler is needed to naturally add volume?

Recently, whenever I take photos, the front of my cheeks look slightly sunken compared to before, and my face as a whole gives off a tired impression, so I am looking into volume treatments. I haven't changed much in weight, but as I get older, I feel like the dimensionality of my face has diminished, and it is difficult to fix with home care alone. I do not want an overly puffy or artificial look, so I would like to consult with you to see if it is possible to naturally fill in only the areas that are lacking using fillers.

I am curious if the required filler volume varies significantly depending on facial shape or the degree of hollowness. I would also like to know the typical starting volume for a first-time treatment and when the effects naturally settle. I would also like to inquire about the price, overall cost, and the duration of the effect that ensures high satisfaction.

I am also curious about how long the filler procedure takes, and the extent of pain, swelling, and bruising. I would like to know if I can go to work or wear makeup the next day if I get the treatment on a weekday, as well as the recovery period and post-procedure precautions. Rather than having a large amount injected at once, I would like to proceed with an amount that suits my face; please let me know if same-day appointments and the procedure are possible after a consultation. Haha.