I have a LG TV & need code for one for all remote URC3021B00

LG started out as Goldstar, merged with Lucky Corp., to become Lucky Goldstar, LG ;-)

Although your remote doesn't list any codes for LG, one of the Goldstar codes may work.
Try 0030, 0056, 0178.

If that doesn't work you may have to try the "Search for Code" feature by first turning your TV on, then follow these steps:

1.On the remote control, press TV once
2.Press and hold SET until the LED (red light) blinks twice,
then release SET.
3.Enter 9 - 9 - 1.The LED will blink twice.
4.Aim the remote control at the TV and slowly alternate
between pressing POWER and TV. Stop when the TV turns off
(after pressing POWER). If the device does not have a Power
key, you can substitute another function, such as digits 0 ~ 9 ,
CH, or PLAY).
NOTE: In the search mode, the remote control will send IR codes from
its library to the selected device, starting with the most popular code
first.
5.To lock in the code, press and release SET.The LED will
blink twice.

The URC-3021 is a 2004 basic model without any learning capability, if you are unable to find a code, it may be time to buy a new remote.
There are newer, low cost universal remotes available at Walmart, Target, K-mart, and other retailers, that should have a more up-to-date code list.

Hope this helps, Greg