No water from shower faucet
 

I have water to sink and toilet but can't get any water flow to tub shower, there is no inside cutoff. What do I need to do.

Both hot and cold?
Not the shower or the tub?

No water at all and it is only one round handle

Shower an tub use same water supply

If you have a tub spout and shower head and no water comes out of either---the cartridge is clogged and needs replacing--

If it's a shower only----it's likely the cartridge---but might be the filter screen at the shower head---unscrew the head and test the valve without it.

We will help you figure out the repair if you give us more details---Mike----