I have 3 bucket fermenters. One of them always bubbles when the beer is fermenting, one never bubbles, and the third has a mind of its own and bubbles when it feels like it. Whether your airlock bubbles or not is not important. The gas given off in fermentation can escape around the lid and never move the airlock. What matters is that the gravity changes as sugars are converted to alochol. You use your hydrometer to tell that.
Now, with all that said, your yeast are probably still building up their population and not yet giving off any gas. Many of my batches don't really get started for 30 to 36 hours if I keep the temperature where it should be. Give yours another day and if it isn't bubbling, carefully open the lid to see if there is krausen or evidence of krausen like a brown bubbly ring around the bucket above the level of the beer.