Toto toilet my toilet does not refill when after i flush. First it started refilling slowly, now it doesn't refill at all

Your fill valve is going bad it can be replace with a new fluidmaster instead of the Ultra-G you have in it its going bad they do over time you may want to check your house water pressure in case that may have been what broke it you don';t want to break a new one.

Most likely the toilet flush valve is plugged with sediment &/or needs to be replaced. Try turning off shutoff valve on bottom of toilet. Then turn valve back on. It may flush out the sediment. If not you will need to change the valve.

Several ideas. Start to fill? Have you looked inside the tank to see what's going on? If it just filling very slowly, then you most likely have some calcuim build up inside your flush valve blocking some flow, if this is the case you will have to clean the flush valve. If your flush valve is staying up and the toilet is "running" unitil the float drops. The float (either the arm ballcock style, or newer fluidmaster) is rubbing on either the flush lever or side of the tank, and taking longer to drop to let the water start flowing. I

hi , replace your flapper on your flush valve assembly .
the link below is a spares dealer in the US
http://www.guillens.com/Toto/Flappers.htm

hope this helps
p.s. these parts do wear out

Sounds like your toilet is not vented properly. Possilbly something caught in the trap is causing it to syphon

Is it not refilling the tank or the bowl? I've got a toto also that is not fully refilling the bowl after each flush. No leaks or other problems. Tank refills fine. Seems that the flapper doesn't float long enough to allow a sufficient amount of water to drain into the bowl before closing. Any ideas?

it sounds like it is not flushing completely at first and then releases and the suction is pulling water out of the bowl. Could be a venting issue or a clog issue that is hindering the proper flushing of the toilet.

I fixed the problem. There was a clog in the pipes so i just flushe dthe pipes out.
thanks,
for your help

yeah sounds as though the ball valve or water inlet valve is stuck in the closed position or jammed so when you flush the loo the water doesnt refill.
Isolate water service remove valve as required clean/replace re instate test & leave working