Question about tax free earnings with SDIRAs

[Christine Oliphant]

I've been learning about SDIRAs and from what I understand when you use the money in your real estate business, the money you earn will be tax free. So as Amanda Han put it in podcast 49, if a wholesaler puts a $1,000 earnest money deposit down and then makes $10K from the deal, those earnings are tax free.

Does this also apply when you fix and flip a property? So if you buy a property for $50K and end up with $30K in profit, those earnings are not taxed?

It doesn't seem like that could be the case since people are doing 1031 exchanges but I'm just trying to figure out the best avenue to save on taxes for fix and flip deals.

Am I understanding this correctly?