It can take 4-6 weeks or sometimes longer for a new tank to cycle. If the tank has a hood/ cover on it, remove the cover to allow bacteria to land in the water.
Increase the water temperature to around 28-30C to help speed the cycling process up. Reduce the temp after the cycle has finished.
Make sure the pH is around 7.0 or slightly higher.
Have lots of aeration/ surface turbulence to maximise the oxygen level.
Add a bottle of filter bacteria to the tank. Use a double dose every day for a week and then pour the remaining contents into the tank. Try to add the supplement near the filter intake so it gets drawn into the filter where it belongs.
You can increase the ammonia to 2-3ppm and see if that helps.
If you have lots of live plants in the tank, then it might not cycle dur to the plants using up the ammonia.