How do train for planche?

I’ve been stuck at tuck planche for around 15 seconds and I can’t figure out how to progress. I’ve been stuck for a month now and I haven’t any really good YouTube videos. Also my lean degree is really low so I don’t know if only leans are the way to improve it. I’ve been trying to set a timeline of 6 months to get to straddle planche but I am not sure if it is a realistic timeline. If anyone has done the progression and got to that stage, please share your advice as it would be greatly appreciated.