Hi I bought a universal remote can you tell me what code to use please?

It should have a guide with the brand names and codes to try. You can also use Google and do a search with the basics, like Vizio TV. It may take a few tries, but you should find a code that works.

Codes should be with the remote, depends on brand and sometimes model.

Weren't there instructions for programming your remote? Google "How to program <fill in remote name>". Print them out for future reference.

I agree... you will most likely be reprogramming again every time you have to replace batteries. Write down the codes and how to program it.. tape it to the back or bottom of the device it controls, you WILL need them again.

You don't mention Manufacture of TV or Remote. Most have several Possible codes to try. Other Option is "Search Mode" , where you progress through a Library of codes.

Smoothy has good advice on saving procedure for the future. Just a note, when batterys need replacing, change batterys quickly, while NOT pressing any buttons.
Usually will keep current programming. Good Luck